I will give you this as a puzzle, so please try to figure out that White's move is going to be. This and a lot of cool other puzzles are presented by IM Andrew Martin in the following video.

[Event "Ch URS"]
[Site "Moscow"]
[Date "1956.??.??"]
[Result "1-0"]
[White "Tigran Vartanovich Petrosian"]
[Black "Vladimir Simagin"]
[ECO "A53"]
[PlyCount "95"]

1. Nf3 Nf6 2. c4 c6 3. Nc3 d6 4. d4 g6 5. e4 Bg7 6. Be2 O-O
7. O-O Bg4 8. Be3 Nbd7 9. Nd2 Bxe2 10. Qxe2 e5 11. d5 c5
12. Rab1 Ne8 13. f3 f5 14. b4 cxb4 15. Rxb4 b6 16. a4 Bf6
17. Kh1 Bg5 18. Bg1 Nc7 19. Rbb1 Na6 20. Nb3 Ndc5 21. Nxc5
bxc5 22. exf5 gxf5 23. g4 fxg4 24. Ne4 Bf4 25. Rb7 Nc7
26. fxg4 Ne8 27. g5 Qc8 28. Re7 Qh3 29. Rf3 Qg4 30. Qd3 Bxh2
31. Rxf8+ Kxf8 32. Rxe8+ Rxe8 33. Bxh2 Re7 34. Nxd6 Qxg5
35. Qf1+ Kg8 36. Ne4 Qh4 37. Qe2 Rg7 38. d6 Qh6 39. Qd1 Qh4
40. Qe2 Qh6 41. Qf1 Rf7 42. Qg2+ Kf8 43. Ng5 Qxd6 44. Qa8+ Kg7
45. Bxe5+ Qxe5 46. Qh8+ Kxh8 47. Nxf7+ Kg7 48. Nxe5 1-0

Did you find it? I have to admit I did not. The game is Tigran Vartanovich Petrosian vs Vladimir Simagin, played in 1956.

[well, no following video, because YouTube just randomly removes content without any way of knowing what it was]

I've been monitoring more closely the access to my blog and I noticed that a lot of people are interested in the post about the Sicilian Wing Gambit, defined as pushing b4 in reply to the standard Sicilian Defense e4 c5. So I will be trying in this to use new knowledge and computer engines to revisit this funky opening gambit. As such I will be using LiveBook, a system created by the people at ChessBase that tries to catalog and discover chess based on active chess games and analysis, as well as computer engines, in this case Komodo 9 with a 256MB table memory. I've continued each variation until there was only 1 game left in the database, then I stopped.

Main line from LiveBook

Let's start with LiveBook. Here is a PGN with the main variations in order of use. You will notice that the main line is to accept the gambit (GM Jan Gustafsson even wrote "take the pawn and be happy!" at that particular junction), then refuse the second pawn and immediately challenge the center - which would have been the Sicilian idea all along - by pushing d5. It loks a bit like a Scandinavian Defense, but without White being able to push the Black queen back with Nc3. The main line shows Black gaining advantage, but then losing it by move 12, where equality sets in. However, the computer does not recognize some of the moves in the main line as best.

In the line that I was interested in, the one where Black takes the pawn on the a-file, White gains the classical center and technically it is ahead in deployment of minor pieces, if one considers a knight on the a-file and a semi blocked in bishop developed pieces. However, not all is lost, as the computer has some ideas of its own. Also keep in mind that the Sicilian Wing Gambit is not well known and few people actively employ it.

So here is the PGN of the LiveBook database, based on what people played: 1. e4 c5 2. b4 {This is the Sicilian Wing Gambit. From here on, the percentages in the comments are wins for White and the points are from computer engines.} cxb4 (2... b6 3. bxc5 bxc5 4. Nc3 Nc6 5. Rb1 g6 6. g3 Bg7 7. Bg2 Ba6 8. Nge2 {50% / 0.00}) 3. a3 d5 (3... bxa3 4. Nxa3 d6 5. d4 Nf6 6. Bd3 Nc6 7. c3 e5 8. Ne2 {50% / -0.33}) (3... e6 4. axb4 Bxb4 5. Bb2 (5. c3 Be7 6. d4 d6 7. Bd3 Nf6 8. Ne2 Nc6 9. O-O O-O) 5... Nf6 6. e5 Nd5 7. c4 Ne7 8. Na3 (8. Qg4 Ng6 9. h4 h5 10. Qg3 Nc6 11. Bd3 {50% / -0.75}) 8... Nbc6 9. Nc2 Ba5 {50% / -0.25}) 4. exd5 Qxd5 5. Nf3 (5. Bb2 e5 6. Nf3 Nc6 7. c4 Qe6 8. Bd3 Nf6 9. O-O
Bd6 10. Re1 O-O 11. axb4 Nxb4 12. Bf1 {75% / 0.00}) 5... e5 6. Bb2 (6. axb4 Bxb4 7. c3 Be7 8. Na3 Nc6 9. Nb5 Qd8 10. d4 exd4 11. Bf4 Kf8 12. Nbxd4 Nxd4 13. Nxd4 {50% / 0.00}) (6. c4 Qe6 7. Bd3 Nc6 8. Bb2 Nf6 9. O-O Bd6 10. Re1 O-O 11. axb4 Nxb4 12. Bf1 {75%}) 6... Nc6 7. c4 Qe6 8. Bd3 Nf6 9. O-O Bd6 10. Re1 O-O 11. axb4 Nxb4 12. Bf1 e4 13. d3 Qd7 14. dxe4 Bc5 15. Bxf6 Qxd1 16. Rxd1 gxf6 {50% / 0.00} *

Computer analysis: main line

Now let's put Komodo on the job, let us know what is going on here. Many people analysed the position resulting after pushing b4 and with depths of 36 and 40, computer engines overwhelmingly suggest taking the pawn. However we might want to explore what happens if we take another option. It is interesting to note that Komodo 9 pushes the main move as the third most important at depth 24. Perhaps later on this would get reversed again, but this soon into the game it just tells us that the other options are equally good. The two moves I am talking about is d5 and e5. Interestingly enough, the second most common human move (b6) is not even on the radar for the computer, while the computer move appears to have been played only 4 times by humans. So let's take a look at computer moves:1. e4 c5 2. b4 d5 3. exd5 cxb4 4. a3 Qxd5 5. Nf3 e5 6. axb4 Bxb4 7. c3 e4 8. cxb4 exf3 9. Qxf3 Qxf3 10. gxf3 * At the end of all this, White has four pawn islands and doubled pawns, but can quickly use the semi open files to attack with rooks. Maybe this discourages you, but remember two things: these are computers making these moves and while the position looks weird, you get attacking chances with no loss of material. That is the purpose of a gambit after all.

Computer analysis: accepting both pawns

Let's see what computers say about the line that we want to happen. The gambit is accepted, the a-pawn is captured as well. What then? I was surprised to see that, depending on depth and engine, the next move is quite different. Stockfish 6, at depth 39 goes with d4, taking control of the center and ignoring the Black a-pawn. The variations from this position are quite complex and have less to do with this gambit. I would gamble (pardon the pun) that the purpose of the wing gambit was reached at this point. Computers give a clear equality between players, but remember that even after we capture the a-pawn, we have still would be a pawn down. Black is forced to passive moves like e6, d6, having to spend resources to regain center control, while most White pieces have clear attack lines.

An example: 1. e4 c5 2. b4 cxb4 3. a3 bxa3 4. d4 e6 5. Nf3 d5 6. e5 Bd7 7. Bd3 Nc6 8. Nxa3 Bb4+ 9. Bd2 Bxd2+ 10. Qxd2 a6 *

Computer analysis: accepting just the first pawn

But what happens in between these two options? What if Black accepts the gambit, but doesn't take the second pawn? Will the computer see the same result as in the "human main line" we first discussed? Not quite. The computer moves are really different from the human ones. 1. e4 c5 2. b4 cxb4 3. a3 e5 4. Nf3 Nc6 5. Bb2 Nf6 6. Nxe5 Qe7 7. Nf3 Nxe4 8. Be2 d5 9. O-O Qd8 10. Bb5 bxa3 11. Nxa3 Bc5 * The result is another equal position, where White lost the center, but has a strong, yet weird development.

Also check out 3... d5: 1. e4 c5 2. b4 cxb4 3. a3 d5 4. exd5 Qxd5 5. Nf3 e5 6. axb4 Bxb4 7. c3 e4 8. cxb4 exf3 9. Qxf3 Qxf3 10. gxf3 Ne7 * An interesting tactic is not to take the d5 pawn and instead advance the e-pawn to e5: 1. e4 c5 2. b4 cxb4 3. a3 d5 4. e5 Nc6 5. Bb2 Qb6 6. Nf3 Bg4 7. axb4 Qxb4 8. Bc3 Qe4+ 9. Be2 Bxf3 10. gxf3 Qf4 11. d4 * You can watch an example game in this variation from Kingscrusher.
My opinion on this is that White forces a strong center, but, as seen from the computer variation, the sides get seriously compromised. The truth is that I always wondered if there is a solid play with the king in the center. This might be it, although keep in mind that in that position White is a pawn down.

What if we start with b4 and then try to move towards the center?

Well, that's easy to answer: it's another opening :) called the Polish or Sokolsky opening and I have written another blog post about it, although it is pretty old. Maybe I will also revisit that one. The point with that opening is that it already shows Black what we plan and it has some other principles of work, more closely related to the English opening to which it sometimes transposes. The Wing Gambit, though, is a response to the Sicilian, trying to pull the opponent from their comfort zone and into ours.

What if we delay the b4 push?

One can wait for the wing gambit until knights have left their castle. That's called the Portsmouth Gambit (1. e4 c5 2. Nf3 Nc6 3. b4) and some consider it stronger than the gambit presented here. It might be interesting to analyse. Haven't found a lot of resources on it, just this 2014 book from David Robert Lonsdale.

Another option is to play 3. a3, preparing a support of b4 on the next move. It does produce similar results as the base gambit, but I didn't have time to analyse it and it feels a bit slow, to be honest.

When Black defends with b6

Defending c5 with b6 leads to a Sicilian without the b-pawns. That means that an attack on the queen side is out and the White light square bishop can linger around on the queen side as long as it wants, targeting that juicy Black king side from afar. Combine that with the dark square bishop having a nice diagonal as well. 1. e4 c5 2. b4 b6 3. bxc5 bxc5 4. Nf3 Nc6 5. Bb5 Nd4 6. Nxd4 cxd4 *
For an example of that variation, check out Kingscrusher's video.

Traps in the Sicilian Wing Gambit

I couldn't find a lot of traps in the Sicilian Wing Gambit. One good video on this comes from GJ_Chess (ignore his Indian accent, he is actually quite good and, what I like a lot, he focuses on traps and dirty tricks in his videos):

Other ideas and nomenclatures

The ECO category for this opening is B20, same as for the Sicilian Defense, which doesn't help a lot.

After Black captures the b-pawn, c4 is called the Santasiere variation of the Wing Gambit, and Black's only option seems to try for control of d4 with either e5 or Nc6. Taking en-passant is giving White a lot of compensation in development.

The goading of the Black pawn with a3 that we've covered above is called the Marshall variation. If Black pushes the pawn to d5 and White captures, we enter the Marienbad variation, while if Black captures the a-pawn, it is called Carlsbad variation. For the record, bad is the German name for bath not an indication that the variation is bad :).

Pushing a3 before b4 is called the Mengarini gambit. Check out a game from 2013 between Dobrov and Blom.

Other resources on the gambit

A nice review of this gambit, with names of the variations and some human analysis, can be found on chess.com. (The same author has a post on The Portsmouth Gambit as well)

On chesstempo there is a nice list of games with this variation that you can search. Play around with the Advanced Search parameters. As a reference, there are 11 games from people over 2500 using the Wing Gambit and White has most wins. If restricting to games after 2000, you only get one, which ended in a draw, although White was better at the end. You can see the game here: Timur Gareev vs Gata Kamsky, US Championship (2015).

Interesting Wing Gambit/Fried Liver attack combo that you can see here: John P. Pratt vs Elden Watson, 29 Sep 1976, Hill Air Force Base, Utah. You gotta love that. Not the best rated players in the world, but still. Here is a lichess computer analysis of the same game.

A 2013 call to reevaluate the Wing Gambit with some examples of famous old games where the opening had a strong effect.

Conclusions

Unlike the Sokolsky opening, the purpose of the Sicilian Wing Gambit is not to push the b-pawn to block Black's development, but to deflect the c-pawn from protecting the center. The goal is reached when White has a strong center. In no way does it mean it is a winning gambit. There are no brutal traps, no quick wins, the only purpose of this opening is to pull an aggressive Sicilian player from their comfort zone and into a slower, more positional one. That means that the White player needs to attack like crazy until Black is a mere smear on the board, otherwise the center control and speed advantage that may be obtained from the opening can be easily lost.

From my analysis I gather that Black should accept the gambit, but not continue to take pawns like the a-pawn, instead focusing on their own piece development and control of the center. With perfect computer play, equality is reached and maintained. White often fianchettoes the dark square bishop to b2 from where they put pressure on the Black king side. Black's game often centers on exchanging pieces, so that the opening advantage gets lost. The best chance Black has to decline the gambit seems to be pushing d5, going into murky territory.

White on the other hand should push for the center, even propping the d-pawn with c3 and blunting the dark square bishop diagonal. Then focusing on attack is the most important feature, as in most gambits.

Careful with the variation in which Black attacks the e4 pawn with d5, then capturing with the queen after the exchange. If not careful the queen can fork the king and the rook. That is why Nf6 is played by White as the next move or even Bb2, although that's not as good, as the bishop can be deflected.

Usually the a-pawn is recaptured with the knight, not the bishop. This may seem surprising, but what it prepares is moving the knight on b5, attacking c7 and a7 and being very hard to dislodge, as the a-pawn is pinned to the rook. Some variations sacrifice the Black rook in the corner for a quick counter-attack. In case it is captured with the bishop, the idea is to exchange dark square bishops and prevent the Black king from castling.

In several games I have seen, moving towards the center forces Black to use e6 followed by d5, to which White can respond with e5 themselves and get into French defense territory. Personally I dislike playing against the French, but in this case, without b-pawns, the theory is quite different as well. For an example, check out this video from Kingscrusher.

Even if caustic GM Roman Dzindzichashvili categorized this as the worst opening for White, don't forget that it was used by Fischer in 1992 to beat Spassky. Well, a transposition thereof. If you are confident in your chess skills, this is just as good an opening as any other and at least you need to know it a little in order to defend against it.

I would love some comments from some real chess players, as all of this is based on game databases and computer analysis. Please leave comments with what you think.

Video examples

Here is Simon Williams using the gambit against a young Polish player:


ChessTrainer shows a nice game where he uses the gambit to get a quick center and take his opponent out of Sicilian main lines:


MatoJelic is showing us some classical games:
Thomas A vs Schmid, Hastings 1952

Wood L vs Mease A ,USA, 1949

There is a nice web site called Chess Pastebin that allows one to publish a chess game as a PGN, comment on it using a Disqus form and share it with whomever you wish. However when I tried to use it, it refused to accept my PGN (extracted from Chess Arena). After many trials I realized that it considered invalid a move written as 10. .. some move instead accepting only 10... some move (no spaces between the dot of the move number and the dots representing a black move after a variation). So just replace ". .." with "..." to get a PGN acceptable by Chess Pastebin.

I was watching a video from GM Niclas Huschenbeth where he played lytura in an online game. Amazingly he lost, but that is what happens when you underestimate your opponent, which I think was what actually went wrong. At the end of the video it was difficult to see exactly what White could have done after a point, so I analysed the game with the computer and found some amazing moves. First I will show you the original game. I urge you to think it through and see what moves you would have done differently, like a chess puzzle, before you watch the game as the computer suggested it. You can also watch the video online at the end of the post and, if you like chess, I really recommend Huschenbeth's channel. Not only is he a great player, but also a decent and nice guy and young, too. His Blitz & Talk GM Special videos are especially cool, since he plays with other world class grand masters.

But enough of that. Here is the game, up to a point where it didn't really matter what happened: 1. e4 e5 2. f4 exf4 3. Nf3 g5 4. Nc3 g4 5. Ne5 Qh4+ 6. g3 fxg3 7. Qxg4 g2+ 8. Qxh4 gxh1=Q 9. Qh5 Nh6 10. d3 d6 11. Bxh6 Be6 12. Bxf8 Rxf8 13. Nf3 Nd7 14. O-O-O c6 15. Bh3 Nf6 16. Rxh1 Nxh5 17. Bf1 Rg8 18. Ne2 Kd7 19. Kd2 Rg7 20. Ke3 Rag8 21. a3 Nf6 22. h3 b6 23. d4 a5 24. Nf4 Rg3 25. Ne2

Here is the video of the game, to give you the time to think it through:


And finally, here are two lines that the computer recommended. This is considering that the fateful 10. d3 was played already: 1. e4 e5 2. f4 exf4 3. Nf3 g5 4. Nc3 g4 5. Ne5 Qh4+ 6. g3 fxg3 7. Qxg4 g2+ 8. Qxh4 gxh1=Q 9. Qh5 Nh6 10. d3 d6 11. Bxh6 Be6 12. Bxf8 Rxf8 13. Nf3 Nd7 14. O-O-O c6 15. Nb5 Nf6 (15. .. cxb5 16. Bh3 Qxd1+ 17. Kxd1 O-O-O 18. Bxe6 fxe6 19. Nd4 {White +1.2}) 16. Nxd6+ Kd7 17. Qh3 Bxh3 18. Bxh3+ Kxd6 19. Rxh1 {Black +0.3}

Did you see those Nb5 and Qh3 moves?! Who does that? :)

Some time ago I started playing chess, got a trainer, played with my colleagues and friends. I felt a passion for the game that I have no idea from where it came and, just as suddenly as it appeared, it vanished. For more than a year I have not even looked at chess videos. I can't say when I would start playing again, not even if I ever would. And it's not because I am not really good at the game :), it is just a matter of random passion.

Passion is probably what made the creators of Lichess create the server. It is a chess site with a very clean interface, a lot of options, even a REST API (that's a programming thing, don't worry about it). Most of all, the site is completely free, no ads, no nags and a mission statement that ensures that the game will remain thus forever. Open source, with a lot of help from the community, Lichess shows a passion for both software development and chess. If I will ever start playing again, it will probably be because of people like these. Thanks, guys!

MinMax or Minimax, as some like to call it, is the basis of most Artificial Intelligence built for games like chess. Its basis is extremely easy to understand: a rational player will try to take the best option available to them, so whatever is good for me the adversary will take as the most likely outcome and he will find the best solution against that outcome. I, following the same pattern, will also look for his best counter move and plan against it. Therefore the thinking for a game of chess, let's say, is that I will take all possible moves, find the one that leaves me with the best position (evaluated by a function from the board position), then look for the similar best play for the adversary. I continue this way until I get to the end of the game or am out of computing resources.

Now, that sounds logical and it's crazy easy to implement. The problem is that for all but the most childish of plays, the tree of all possible moves increases exponentially. And chess isn't even one of the worst games to do that. Imagine Tic-Tac-Toe, a game played on a 3x3 board between two players. You have a total of 9 possible moves to choose from as the first player, then 8, then 7, etc. The entire game tree has a total of 9! possible moves, or 362880. But generalize the game to a board of 10x10 and a winning rule of 5 in a line and you get 100! moves, which is less than 1E+158, that is 10 followed by 158 zeros.

That's why the so called pruning was created, the most common of all being Alpha-Beta, which tries to abort the processing of leaves that seem to reach a worse situation than their parent node. Of course, all of this is the general gist. You might want to take into account a number N best moves from the opponent, as well as try a more lenient pruning algorithm (after all, sacrificing a piece brings you to a worse position than when you started, but it might win the game). All of this increases, not decreases the number of possible moves.

And now comes my thought on this whole thing: how can I make a computer play like a human when the core edict of the algorithm is that all participating players are rational? Humans are rarely so. Mathematically I could take N, the number of best moves I would consider for my opponent, to be the total number of moves my opponent could make, but it would increase the exponential base of the tree of moves. Basically it would make the algorithm think of stupid things all the time.

The pruning algorithm seems to be the most important part of the equation. Indeed, I could consider the move choice algorithm to be completely random and as long as I have a perfect pruning algorithm it will remove all the stupid choices from me and let me with the smart ones. A quote comes to mind: "you reach perfection not when you have nothing else to add, but when there is nothing left to remove". It's appropriate for this situation.

Now, before attacking an algorithm that has survived for so long in the AI industry (and making my own awesome one that will defeat all chess engines in the world - of course, that's realistic) I have to consider the alternative algorithm: the lowly human. How does a human player think in a game of chess? First he surveys the board for any easy wins. That means a broad one or two levels analysis based on a simple board evaluation function. Immediately we get something from this: there might be multiple evaluation functions, we don't need just one. The simple one is for looking for greedy wins, like "He moved his queen where I can capture it, yay!".

The same outcome for situations like this would be achieved by a MinMax algorithm, so we ignore this situation. It gets more interesting from now, though. We look for the moves of the most active pieces. I know that this is the rookie system, but I am a rookie, I will make my computer algorithm be as stupid as I am, if I am to play it, so shut up! The rookie will always try to move his queen to attack something. It's the most powerful piece and it should get the most results for the least effort. We left Greed behind, remember? We are now doing Sloth. Still, with a good pruning algorithm we eliminate stupid Queen moves from the beginning, so considering the Queen first, then Rooks, then Bishops, then Knights, etc. is not a bad idea. The order of the pieces can be changed based on personal preferences as well as well established chess rules, like Knights being better that Bishops in closed games and so on.

This is a small optimization, one that probably most game engines have. And we haven't even touched pruning; boy, this is going to be a long article! Now, what does the human do? He does the depth first tree searches. Well, he doesn't think of them like that, he thinks of them as narrative, but it's basically a depth first search. This is the casual "What if...?" type of play. You move the Queen, let's say, bringing it right in the enemy territory. You don't capture anything important, but to bring a strong piece this uncomfortably near to the enemy king is scary. You don't play for game points, but for emotion points, for special effects, for kicks! You don't abandon the narrative, the linear evolution of your attack, until you find that it bears no fruit. It's the equivalent of the hero running toward the enemy firing his pistol. If the enemy is dumb enough to not take cover, aim carefully and shoot a burst from their SMGs, you might get away with it and it would be glorious. If not, you die idiotically.

It is important to note that in the "Hollywood" chess thinking you are prone to assume that the enemy will make mistakes in order to facilitate your brilliant plan. The evaluation goes as follows: "I will try something that looks cool if the chances for a horrible and immediate loss are small". When some hurdle foils your heroic plan, you make subplans that would, as well as you hope, distract the adversary from your actual target. This, as far as I know, is a typical human reasoning type and I doubt many (if any) computer game engines have it. In computer terms, one would have to define a completely new game, a smaller one, and direct an AI designed specifically for it to tell you if it would work or not. Given the massively parallel architecture of the human brain, it is not hard to understand why we do something like this. But we can do the same with a computer, mind you. I am thinking of something like a customized MinMax algorithm working on few levels, one or two, as the human would. That would result in a choice of N possible moves to make. Then construct a narrative for each, a depth search that just tries to get as much as possible from each move without considering many of the implications. Then assign a risk to each level of this story. If the level exceeds a threshold, use the small range MinMax at those points and try to see if you can minimize the risk or if at that point the risk makes your narrative unlikely.


Let's recap the human thinking algorithm so far:

1. Try to greedily take what the opponent has stupidly made available
2. Try to lazily use the strongest piece to get the most result with the least effort
3. Try to pridefully find the most showy move, the one that would make the best drinking story afterwards
4. Try to delegate the solving of individual problems in your heroic narrative to a different routine

Wow! Doesn't it seem that the seven deadly sins are built-in features, rather than bugs? How come we enjoy playing with opponents that pretty much go through each of them in order to win more than we do with a rational emotionless algorithm that only does what is right?

Again, something relevant transpires: we take quite a long time imagining the best moves we can make, but we think less of the opponent's replies. In computer terms we would prune a lot more the enemy possible moves than we would our own. In most rookie cases, one gets absorbed by their own attack and ignores moves that could counterattack. It's not intuitive to think that while you are punching somebody, they would choose to punch back rather than avoid the pain. In chess it's a little bit easier and more effective, since you can abandon a piece in order to achieve an overall gain in the game, but it can and it is done in physical combat as well.

Okay, we now have two alternatives. One is the logical one: take into account all the rules chess masters have taught us, shortcuts for achieving a better position on the board; choose moves based on those principles and then gauge the likely response from the opponent. Repeat. This is exactly like a MinMax algorithm! So we won't do that. The hell with it! If I can't enjoy the game, neither will my enemy!!

Human solution: don't do anything. Think of what your opponent would do, if you wouldn't move anything and foil their immediate plan. This way of thinking would be counterintuitive for a computer algorithm. Functioning on the basis of specific game rules, a computer would never be inclined to think "what would the enemy do if I didn't move anything, which is ILLEGAL in chess?". That makes us superior, obviously ;-)

Slowly, but surely, a third component of the algorithm becomes apparent: the move order choice. Let's imagine a naive MinMax implementation. In order to assess every possible move, it would have to enumerate them. If the list of moves is always the same in a certain board position, the game will always proceed the same way. The solution is to take the list of possible moves, but in a random order. In the case of the "human algorithm" the ordering becomes more complex (favouring powerful piece moves, for example). One could even consider the ordering mechanism responsible for choosing whether to do a careful breadth search for each level or a depth first one.


Here is a suggestion for an algorithm, one that takes into account the story of the game and less the objective gain or position strength:

1. For each of your power pieces - anything but the king and pawns - compute mobility, or the possibility to move and attack. Favour the stronger pieces first.
2. For each power piece with low mobility consider pawn moves that would maximize that mobility.
3. For each power piece with high mobility consider the moves that would increase the chance of attack or that would attack directly
4. For each strong move, consider the obstacles - enemy pieces, own pieces, possible enemy countermeasures
5. Make the move that enables the considered power move or that foils the enemy attempts of reply

The advantage of this approach is that it only takes into account the enemy when he can do something to stop you, the pawns only when they can enable your devious plan and focuses on ventures that yield the best attack for your heroes. For any obstruction, you delegate the resolution of the problem to a different routine. This makes the algorithm parallelizable as well as modular - something we devs love because we can test the individual parts separately.

This algorithm would still use a board estimation function, but being more focused on heroic attacks, it would prefer interesting move orders to static positions as well as the "fun factor", something that is essential to a human-like algorithm. If the end result of the attack is a check-mate, then it doesn't really matter what position estimate you get when you did half the moves. All one has to wonder is if the attack is going to be successful or not and if one can do something to improve the chances of success. And indeed this is one of the most difficult aspects for a chess playing human: to switch from a failing plan to a successful plan when it is not yet clear is the first plan is failing. We invest energy and thought into an idea and we want it to work. A lot of the chess playing strategy of human rookies relies on prayer, after all. A computer would just assess the situation anew at every move, even if it has a strategy cached somewhere. If the situation demands it, a new strategy will be created and the last one abandoned. It's like killing your child and making another!


But, you will say, all you did so far was to describe an inferior algorithm that can be approximated by MinMax with only custom choices for the pruning and move order functions! You are missing the point. What I am describing is not supposed to beat Grand Masters, but to play a fun game with you, the casual player. More than that, my point is that for different desired results, different algorithms must be employed. This would be akin to creating a different AI for each level of a chess game.

Then there is the issue of the generalized TicTacToe or other games, such as Arimaa, created specially to make it difficult for computer algorithms to play, where MinMax fails completely. To make a comparison to real life, it's like you would consider the career steps you would take in life based on all possible jobs available, imagining what would it be to be employed there, what the difficulties might be, finding solutions to those problems, repeating the procedure. You will get to the conclusion that it is a good idea to become a computer scientist after thoroughly examining and partially understanding what it would be like to be a garbage man, a quantum scientist, a politician and a gigolo, as well as all the jobs in between. Of course, that is not as far fetched as you think, since in order to be a success in software development you must be at least a politician and a garbage man, perhaps even a gigolo. Lucky for our profession, quantum computers are in the works, too.

The same incongruency can be found when thinking of other games humans enjoy, like races. The desired result can only be achieved at the end of the race, when you actually get somewhere. In order to get to that specific point in space, you could consider the individual value of each direction change, or even of each step. However humans do it differently, they specify waypoints that must be achieved in order to get to the finish and then focus on getting from waypoint to waypoint, rather than rethinking the entire course. In computer terms this is a divide-and-conquer strategem, where one tries to solve a problem that has known start and end points by introducing a middle point and then solving the problem from the start to the middle. BTW, this also solves Zeno's paradox: "Why does the arrow reach its target if, at any point in its course, it has at least half the distance left to fly?" and the answer is "Because of the exit condition that prevents a stack overflow". Try to sell that one in a philosophy class, heh heh.


So why aren't chess AIs based on human thinking processes? Why don't they implement a divide and conquer solution for a game that always starts with a specific board position and ends in capturing a specific piece? Why do chess engines lower their "level" by sometimes randomly choosing a completely losing path instead of something that is plausible to choose, even if completely wrong objectively? How can MinMax be the best general algorithm for game AIs, when some of them have a branching factor that makes the use of the algorithm almost useless?

I obviously don't have the answers to these questions, but I may have an opportunity to explore them. Hopefully I will be less lazy than I usually am and invent something completely unscientific, but totally fun! Wish me luck!

I've had some changes in my life lately and more are coming so I took a break from chess, but I found a bit of time to finish this chess puzzle book that I started reading a few months ago, but never quite got around to complete. Chess Tactics for Champions is not really for champions, but for beginner to intermediate level, or at least this is what it felt like to me. Susan Polgar chose to structure the book into chapters of about 25 puzzles or examples, each covering some important aspect of chess tactics. Here is a list of those chapters:

• 01 - Forks and double attacks
• 02 - Pins
• 03 - Deflection/removing the guard
• 04 - Discoveries
• 05 - Double check
• 06 - Skewers
• 07 - Trapping pieces
• 08 - Decoys
• 09 - Intermediate moves
• 10 - Pawn promotion
• 11 - The back-rank problem
• 12 - Destroying the castled king's protection
• 13 - King chase
• 14 - Mixed checkmates in two moves
• 15 - Mixed checkmates in three moves
• 16 - Mixed checkmates in four moves
• 17 - Game-saving combinations
• 18 - Perpetual check
• 19 - Stalemate
• 20 - Traps and counter traps
• 21 - Sibling positions
• 22 - Twenty-five famous combinations

The last two chapters are presentational only, but the first 20 contain puzzles that the reader must solve, with solutions at the end of the chapter. The authors tried to order the chapters by complexity, so that beginners could understand and solve the first chapters and then move over to the more advanced positions, but it is not always so. It seemed to me that, for most of the chapters, the last two puzzles are especially chosen for the "wow!" factor.

The bottom line is that the book is not just something you read. You solve the puzzles, some are frustrating, some are beautiful, most can be "seen" without a board in front of you - for the last chapter I would advise a board, though - but one can return to this book again and again. For example myself, once I get around to chess again, I might go through the book, just to get into the solving mindset that is essential to beautiful play. Now, I don't know how other chess puzzle books are, this being my second chess book I have read, but I imagine some could be a lot better. However, the structure of Chess Tactics for Champions makes it very easy to use as a reference book. One thing I felt was missing was pawn play. Of course, that often enters the category of strategic play, rather than tactic, but still.

More about the authors at Wikipedia: Susan Polgar and Paul Truong. They have been married since 2006.

As I mentioned in previous posts, I've started a chess learning program with a professional, so I can increase my understanding of the game. I was tired of watching Dennis Monokroussos' videos and understanding little of them. Why was he able to breeze through openings and only start explaining from move 20 or so? Why are the chess masters that I watch on videos able to say "this cannot be taken because of..." followed by a four move scheme that makes obvious the mistake, but that I couldn't see it?

And so I got this Romanian dude, Catalin Carmaciu, as an instructor. He may be a bit off putting at first, as it seems he is willing to teach you for free and show you everything he knows, give you any material you ask for and even take time to analyse your games, with any sort of payment as your choice. So, if you don't like open generous guys who are also very smart, I don't recommend him. Otherwise, he is great! His chess site is in Romanian. Anyway, he looked at the deplorable state of my chess understanding and said "What do you want to do? Win games or learn to be better?" I said I wanted both, of course, as any decent Neo who would swallow both pills. Of course, it is not easy. You might want to ask about the difference between the two. Isn't it obvious that if you play the game better you will also win more games? What kind of choice is that? And the answer is that for winning games you acquire a repertoire of openings and defences which you learn and exercise repeatedly, while for playing better you read and exercise tactics and strategy books.

My first reaction was disappointment. Here there was this brilliant chess player telling me I had to mechanically learn a series of openings, while I wanted to understand the concept of chess as a whole. But I was wrong to feel that way. You see, since then we've decided on four openings: two defences for standard White openings (e4 and d4) and two replies to defences by Black to my opening with e4 (e5 and c5). While at first it seems you learn some moves in a mechanical way and your only advantage is previous knowledge of a situation that you set up, the reality of it is that you choose the setup and for each you have a long term plan! In the middle game and end game you have a clear vision of what you want, where the attack goes, where to hinder the enemy's movements and what are the triggers for each. It would have been easy to say "for any possible game, you must make a strategic plan before you play", but unless you know what you are doing, that plan would suck. So, while playing these apparently memorized openings, I've developed a practice and an understanding of strategic planning in chess. I have also found answers to other, less common, openings. For example White might move Nf3, but that prohibits me playing e5, so I go with the d5 plan which was originally designed to stop White's d4. And behold, White then plays d4, transposing into a standard d4 opening.

Wait a minute, you jump, but you said the other "learning branch" was the one where you learned tactics and strategy! It is true: strategic thinking is exercised in both situations, only the first is somehow more adult: you learn by doing. Oh, I do have some tactics books that I am looking through and some general strategy books that are supposed to be awesome, but until I find the time and disposition to focus on them and read carefully and understand what is written there, I have the option of playing chess and learning as I go.

Another thing about getting a chess instructor is that he isn't doing much. There is no magical method that he can wield that improves your chess. Instead he instructs you on what is good to do and you must do it. The effort is yours. The bonus comes from his filtering the chess materials so you get the ones that actually help you. The rest is up to you. After a week of playing, he may look at your chess games and quickly tell you where you went wrong, but they have to be your games.

One thing that my instructor is adamant about is not to use chess engines to analyse your games. That's right! He is telling a computer programmer to not use computer programs for chess. I know, a bit off putting, but he finally convinced me completely when he said that after a (simulated) rating of 2000 ELO, the computers don't move anything like a human. As a 2500 player himself, he cannot prepare for chess championships or games with other players by playing with a computer. His method of analysis is personal: take your game, think of what you thought when you made the moves, see what went wrong with your plans, see what better moves you could have done. It makes sense, after all, to not use computer programs to analyse your strategic plans, since they don't have any.

So, in order to summarize, my solution for learning to play better chess is to find the opening repertoire that you want to use for most chess games. You don't do that in order to trap the other into little known situations, as I did for a while, but in order to set up a game where you are aware of the strategic plans that you and your opponent are prone to use. In the end the order of the moves might be different, the situation may change one way or another, but as long as you follow the plan, you should be OK.

Yes, yet another chess blog post. Don't worry, soon there will be a ton of rants about the programming world, just wait a bit.

This puzzle is from Chess Tactics for Champions, by four times women chess champion Susan Polgar. Here is a review of the book, much better than I could do it. So, on to the puzzle:

White to move.


[SetUp "1"]
[FEN "1k1r4/pP2q3/8/Q5pP/5bP1/5P1K/P1R5/8 w - - 0 1"]
1. Rc8+ Rxc8 2. Qxa7+ Kxa7 3. bxc8=N+ *

I have started a more formal chess training program, something that would possibly improve my skills as a chess player and finally getting me into that place where I can fully appreciate the beauty of the game. As part of this program I've watched the Daniel King Power Play DVD Part 1: Mating Patterns, in ChessBase format. It was a well presented material that made for very interesting time. The information contained is aimed at beginners such as myself and presents several chess mating themes, with some puzzles at the end, to test the knowledge gain. I can say that I liked it and I recommend it to other learning chess players as well. However, this post is aimed at summarizing the information, for future reference.

Themes:
1. Greek Gift
2. Lasker Double Bishop sacrifice
3. Lawnmower (Double Shotgun) mate
4. Bishop See-saw
5. H-file Rook distraction
6. Knight mate
7. Queen in on the pin
8. Back rank mate

And then are the Puzzles.

For each theme I will post pictures with a position, let you think, then give you the opportunity to see the entire PGN. Same with the puzzles. Try to think things through before looking for the solution.

1. Greek Gift

The opposing king is castled short and you sack a bishop by taking the pawn in front of the enemy king. The king is forced to take, and then a knight check comes, followed by the arrival of the queen.

Netzer, Jean - Guezennec, Franck, 2000 (FRA-chT U20)

White to move. Click here to see the game.

Hartl, Rainer - Hecht, Christoph, 2000 (Landesliga Sued 0001)

White to move. Click here to see the game.

Langrock, Hannes - Gaede, Derek, 2000 (JBLN West 0001)

White to move. Click here to see the game.

Polugaevsky, Lev - Tal, Mihail,1969 (URS-ch37)

White to move. Click here to see the game.

Colle, Edgar - O'Hanlon, John,1930 (Nice)

White to move. Click here to see the game.

Thesing, Matthias - Borngaesser, Rene,1984 (NRW-ch)

Black to move. Click here to see the game.

Toulzac, Pierre Yves - Sokolov, Andrei,2000 (Mulhouse IM)

White to move. Click here to see the game.

2. Lasker Double Bishop Sacrifice

The light bishop is sacrificed just like in the Greek Gift, the queen comes around to check, then the dark bishop is sacrificed as well for the pawn in front of the enemy king. The mate is achieved by a rook lift.

Lasker, Emanuel - Bauer, Johann Hermann, 1889 (Amsterdam)

White to move. Click here to see the game.

Koenig - Cornforth, 1952 (London)

White to move. Click here to see the game.

Dizdarevic, Emir - Miles, Anthony , 1985 (Biel MTO op)

Black to move. Click here to see the game.

Jonkman, Harmen - Espig, Lutz, 1998 (Chemnitz op)

White to move. Click here to see the game.

3. Lawnmower (Double Shotgun) mate

Two rooks or a rook and a queen push the enemy king to the margin of the board, taking rank after rank or file after file until the king is mated

King, Daniel J - Krasenkow, Michal, 1989 (GMA Baleares op)

White to move. Click here to see the game.

Tkachiev, Vladislav - Watson, William N, 1993 (London Lloyds)

White to move. Click here to see the game.

Watson, William N - Merriman, John, 1993 (London Lloyds)

Black to move. Click here to see the game.

Bologan, V. - Van Haastert, E., 2005 (21st ECC)

Black moves h5, White to move. Click here to see the game.

4. Bishop See-saw

The queen has caught the enemy king at the corner of the board, his only escape blocked and continuously harassed by a bishop that gobbles all the pieces on its color and then gives mate.

From Nimzowitsch's book My System

White to move. Click here to see the game.

King, Daniel J - Kuijf, Marinus, 1982 (Amsterdam)

White to move. Click here to see the game.

5. H-file Rook Distraction

The enemy king seems safe, as your pieces appear uncoordinated, but here comes a suicidal rook bringing the king into the open and ready to be slaughtered.

Polgar, J. - Berkes, F., 2003 (Hunguest Hotels)

White to move. Click here to see the game.

Kuemin, Simon - Cebalo, Miso, 2003 (Biel MTO)

White to move. Click here to see the game.

Kudrin, Sergey - King, Daniel J, 1988 (London NWYM)

White to move. Click here to see the game.

Sorensen, Arne - Marciano, David, 1988 (Tecklenburg op)

White to move. Click here to see the game.

Kuzmin, Gennadi P - Zhuravliov, Valerij, 1992 (St Petersburg)

White to move. Click here to see the game.

6. Knight Mate

Mates with the knights, whether in conjunction with other pieces or with other knights.

Kotronias, Vasilios - King, Daniel J, 1990 (New York WFW)

White to move. Click here to see the game.

Wheeler, G. - Povah, N., 1977 (London)

White to move. Click here to see the game.

De Musset, A. - study

White to move. Click here to see the game.

Clemenz - Eisenschmidt, 1862 (Dorpat)

White to move. Click here to see the game.

Dumpor, Atif - Kosic, Dragan, 2001 (Ajvatovica IM)

Black to move. Click here to see the game.

Kortschnoj, Viktor - Karpov, Anatoly, 1978 (World Championship 29th)

White to move. Click here to see the game.

7. Queen in on the pin

The queen comes right next to the enemy king, where the poor protecting pieces are pinned by some other piece. The opposing king is stuck between his pieces and the troublesome queen.

Tatai, Stefano - Kortschnoj, Viktor, 1978 (Beersheba)

Black to move. Click here to see the game.

King, Daniel J - Costa, Jean Luc, 1987 (Bern)

From here, Black will move Ne4, then White to move. Click here to see the game.

Fazekas - Spielmann, 1938 (Prague)

White to move. Click here to see the game.

Peredy - Malanca, 2003 (Budapest)

Black to move. Click here to see the game.

8. Back rank mate

The poor enemy king is attacked and there is nowhere to go because of his own protectors.

Wolff, Patrick G - King, Daniel J, 1989 (London WFW)

White moves Rab1, Black to move. Click here to see the game.

Rovner - Kamyshev, 1947 (Moscow)

White to move. Click here to see the game.

Capablanca - Fonaroff, 1918 (New York - casual)

White to move. Click here to see the game.

Alden - Nilsson, 1972 (Sweden)

Black to move. Click here to see the game.

Adams, Michael - Giorgadze, Giorgi, 1997 (FIDE-Wch k.o.)

White to move. Click here to see the game.

Alekhine, Alexander - Colle, Edgar, 1925 (Paris)

White to move. Click here to see the game.

Bazan, Osvaldo - Fischer, Robert James, 1960 (Mar del Plata)

Black to move. Click here to see the game.

Puzzles

Think it through, prepare your moves in your head and only then look at the games.

Cinak, Nilufer - Novak, Ksenija, 2002 (Bled ol (Women))

White to move. Click here to see the game.

Bareev, Evgeny - Akopian, Vladimir, 2000 (Dortmund SuperGM)

White to move. Click here to see the game.

Sveshnikov, Evgeny - Sherbakov, Ruslan, 991 (URS-ch58)

Black will move g6, White to move. Click here to see the game.

Hillarp-Persson, Tiger - Hansen, Sune Berg, 2005 (Sigeman Chess Tournament 2005)

White to move. Click here to see the game.

Marin, Mihail - Kiselev, Sergey, 1997 (Ciocaltea mem)

Black to move. Click here to see the game.

Yates, Frederick - Reti, Richard, 1924 (New York)

White to move. Click here to see the game.

Jussupow, Artur - Ivanchuk, Vassily, 1991 (Candidates qf3)

White to move. Click here to see the game.

Bruzon, Lazaro - Jobava, Baadur, 2005 (Capablanca Memorial Elite)

White to move. Click here to see the game.

Vidmar - Euwe, 1929 (Karlsbad)

White to move. Click here to see the game.

Rozentalis, Eduardas - Kozul, Zdenko

White to move. Click here to see the game.

Azmaiparashvili, Zurab - Shirov, Alexei, 2002 (FIDE GP)

Black to move. Click here to see the game.

I know it has been a long read, but imagine how long it took me to write it! This is not something you read once, but a post that you return to again and again to rehearse the games and maintain the feel for these interesting mates.

Also, there are some inconsistencies between the start of the game and the pictures, also the puzzles are not very clear. It should have a text that explains what you are to try to do. And there are comments in German in the PGNs, as well. I am going to address this.

As you may have guessed from my previous chess posts, I am a chess beginner and a gambiteer. I like to play the strange moves and see my opponents squirm in positions that they were not expecting and were not prepared for. That is why the proposition in this post is gambit galore and also to be taken with a grain of salt.

My idea is that there could be common themes for the three Gambits in the title, since they start almost the same way. You have the Smith-Morra Gambit, where White answers Black's Sicilian Defence with d4 and then c3 in the accepted version:1. e4 c5 2. d4 cxd4 3. c3 dxc3 4. Nxc3 * then you have the Danish Gambit, where White's move order is the same in response to King's pawn defence: 1. e4 e5 2. d4 exd4 3. c3 dxc3 4. Nxc3 * and then there is the similar response from Black to the King's pawn opening, called the Elephant gambit: 1. e4 e5 2. Nf3 d5 3. exd5 *

You might notice that in the Elephant, I did not offer up a second pawn on c6. This is because the main line is pawn to e4 and also White has the opportunity to take e5 with the knight, which is the computer recommendation as well. The problem is that after Black's response Qe2 to the main line or the Bd6 computer recommendation after Nxe5, the Elephant doesn't appear at all like the Danish/Morra and, instead, threads into its own territory, somewhere closer to the Latvian gambit, but not by much. However, in this post I will be stretching the imagination and will be trying to squish the big Elephant into the Morra mold and see where it takes me.

I have just finished watching a two hour video presentation of the Morra accepted line, by IM Andrew Martin, and there are also a lot of tutorials for the Danish, from beginner to very advanced levels. Not so for the Elephant, which seems to be even less favoured than the Latvian, to which GM Roman Dzindzichashvili answered with a refutation and some very rude words to its efficacity. All that I could find about it are lines that have no connection with the Danish/Morra style and that is because of that pesky White knight on f3.

If my thesis holds ground, then I will be talking here about a chess system that has some similar ideas and theory for at least three major openings: The Sicilian Defence and King's pawn for both White and Black! Also, threading on less travelled ground, there is a good chance online and club players will be unnerved by it.

So let's get into it. I will start with the Smith-Morra main line. This means the most played version in database games, by players who know theory and open that way because it was proven to be the best way. There is little chance you will see the same moves in club level games.

1. e4 c5 2. d4 cxd4 3. c3 dxc3 4. Nxc3 Nc6 5. Nf3 d6 6. Bc4 e6 7. O-O Nf6 8. Qe2 Be7 9. Rd1 e5 10. h3 O-O 11. Be3 a6 12. Rac1 *

This is the position in which White wants to get. I tweaked a little the game so that at move 11. Black moved to the second most used line in the database, the a6 system, rather than Be6 and exchange light bishops. What I want to evidence here is the position of the White pieces: both rooks are connected and on open or semi-open files, cramping Black's development, the bishops are out and about, aiming at the Black king, the knights are developed and the queen is on a very crucial square, controlling yet another file and the essential e2-c4 diagonal.Black has not finished development, has pinned pawns and weaknesses like b6 where a knight may find outpost. There is a lot of potential for attack and, even before reaching this position, a lot of possible traps in which Black could fall. Even the main line has only about 100 games in the database at this point, so it is not very common, even if it is a pretty solid opening.

Let's move to the Danish and compare.

1. e4 e5 2. d4 exd4 3. c3 dxc3 4. Nxc3 Nc6 5. Bc4 Nf6 6. Nf3 d6 7. Qb3 (7. O-O Be7 8. Qe2 O-O 9. h3 a6 10. Rd1 b5 11. Bb3) 7... Qd7 8. Ng5 Ne5 9. Bb5 c6 10. f4 cxb5 11. fxe5 *

Seems to be a different beast altogether. I've added a variation that plays like the Morra, the single game in the database like that (Sipek-Urbanec 1995). The b5 push is also found in the Morra. So, what are the differences here? The most important to me seems the absence of the Black pawn on e6. That means White can attack much quicker and Black must defend more aggressively, too. The e4 pawn is unopposed and, in some games, that proves decisive for White. The pawn on c7 is still there, so the Black queen will have to maneuver on light squares instead of dark.

A possible conclusion would be that, even if they seem similar, the Danish and Morra gambits are quite different. But are they?

A White queen on e2 would support the e4 pawn in its push forward and make room for a rook on d1, just like in the Morra. The dark bishop can pin or eventually trade with the knight on f6 or even move to e3 or f4, supporting the e4 pawn as it moves to e5 and making room for a rook on c1. A computer analysis on a Danish game played in the Morra fashion shows equality when Black still has an extra pawn.

Now, some of the readers may scoff and conclude that I am trying to fit the proverbial triangle shape into the round hole using brute force, that attempting to take one opening and play it like another is an imperfect chimera, destined to be an abomination. However, I must remind you that I am not a master player, nor a professional one. I have no time to learn tons of theory just to win a game. My purpose for this research (which may still fail to achieve anything) is to find a gambit based system that uses the same principles for any opponent response. In time, each variation can be improved and branched off from the main system, but at the start all I need is for it to work.

Let's get back, then. How about playing a Morra game in the Danish way? Well, the Danish gambit is even rarer than the Smith-Morra and the games in my database are primarily focused on the exposed f7 square. It could work, I guess, but it would seem even more unnatural and, lacking proper theory, a beginner like me could easily mess it up. I will, therefore, use the Morra as the template to which all others must conform.

Besides, if you think fitting the Danish to the Morra was difficult, the Elephant comes next!

In the database there are only two games that start like a Morra Elephant and they both are won by White, which is not good for us. Only when it gets to the standard position of knight protecting the single center pawn, the transposed games suddenly reach 73! It seems this position can be more easily achieved by playing the Scandinavian defence! In the next board I will present the main line for the Elephant, then the Morra Elephant and at the same time the way to reach the same position from the Scandinavian. The rest will continue from the Elephant line, but, actually, it will be based more on Scandinavian games.

1. e4 e5 (1... d5 {The Scandinavian Defence} 2. exd5 c6 3. dxc6 Nxc6 4. Nf3 e5 {And we reach the position would would have liked from the Morra Elephant.}) 2. Nf3 d5 3. exd5 e4 (3... c6 {And here is a Morrafication of the Elephant} 4. dxc6 Nxc6 5. Bb5 Bd6 6. O-O Nge7 7. d4 e4 8. Ne5 Bxe5 9. dxe5 O-O 10. Qxd8 Rxd8 11. Nc3 Nxe5) 4. Qe2 {This is how the Elephant is mainly played.} Nf6 5. Nc3 Be7 6. Nxe4 O-O 7. d3 Nxd5 8. Qd1 Nc6 9. Be2 Bf5 10. O-O Qd7 *

Ooh! This seems completely different. White still has that extra tempo and he uses it to pin the Black knight on c6, which leaves e5 undefended. Black's bishop on f8 did not have time to get out, so moving the queen on e7 like in the Morra would block it and the entire king side. The move Bd6 is the only one that can defend the pawn and this gives White at least the opportunity to swap the bishop with the knight and mess up the Black pawn structure on the queen side. If White does not take, as in the example above, then the only possible move to protect the knight is to use the other knight on e7, thus forever altering the structure of the game.

It seems no amount of force will twist the Elephant into a Morra gambit a tempo behind. A Morra with a lost tempo doesn't even appear to work! Besides, in order to get here, White had to ignore the opportunity in the beginning to take on e5 with the knight, as suggested by the computer; a much safer route to the same dysfunctional position can be achieved from the Scandinavian defence.

The Elephant hides some interesting traps that have nothing to do with the Morra or the Danish and has more in common with the Latvian gambit that with the two systems above. The Latvian, if you remember, offers up two pawns in order to gain the tempo White is awarded in the start of a chess game. The Elephant can be played in the same way, only to lose two center pawns, so not so good. The similarities with the Morra/Danish are deceiving. A tempo behind, Black cannot use the same ideas, having to defend instead of attack.

Conclusion: It is a very difficult thing to find a defence for Black that works the same way as an opening for White, because of the extra tempo. Even so, the Elephant only begins like the Morra, it has nothing else in common. The Morra gambit itself is only similar to the Danish and, while I think they can be molded in the same shape, it would be a tortuous adventure that I am not sure will get me where I want.

I hope you have gained a little understanding of the differences between the three gambits and how simple differences like the position of a pawn or an extra tempo can change a game of chess.

I want to present to you a game I had last night that was both spectacular and really silly :) You know when you look at chess master games and you are either bored by their precision or befuddled by their ingenuity? Well, this is only a really good show, the equivalent of big budget action movies.
1. e4 c5 2. b4 {The Wing Gambit, a weird anti Sicilian move that I want to
master.} cxb4 3. a3 bxa3 4. Bxa3 {At this point White has control of the
center and a developed minor piece. The rook also has a semi open file
available.} a6 5. Bc4 d6 6. Nf3 e6 7. O-O Be7 8. d4 Nf6 9. Re1 O-O 10. Nc3
Nc6 {Even if I wrote a blog entry on the Wing Gambit, I remembered nothing
and my opponent was so terrified that he tried to protect everything with
unnecessary pawn moves.} 11. e5 {I had no plan and it shows. I was planning
to take on e5 with the rook, eventually, or free my queen by actively
moving the knight on f3.} Ne8 12. Bd3 d5 13. Bb2 {I've decided that I
needed that bishop and moved it to protext the defenceless knight. However,
that is no longer an active square for it.}

(13. Bxe7 Qxe7 14. Na4 Nb4 15.
Bf1 b5 16. Nc5 {The computer suggested this weird continuation, were both
knights are trying to find outposts in the opponent's teritory.})

13. .. f6
14. Nh4 {I had come up with a daring stratagem, enacted in the next few
moves. Can you spot it?} Nxd4

(14. .. fxe5 15. Bxh7+ Kxh7 16. Qh5+ Kg8 17.
Ng6 exd4 18. Ne2 Nf6 19. Qh8+ Kf7 20. Nxf8 Qxf8 21. Qh3 Kg8 {Houdini
recommends a different approach for Black, something that would have
brought it into an advantageous position.})

15. Bxh7+ {The attack begins
with a minor piece sacrifice.}

(15. Nxd5 Qxd5 16. Bxd4 f5 17. Nf3 {The
computer had other ideas, which were almost as wild as what I was
considering.})

15. .. Kxh7 16. Qh5+

(16. Qxd4 fxe5 17. Rxe5 Bxh4 18. Rh5+ Kg8 19. Rxh4 Qf6 20. Qxf6 Nxf6 {The computer would have equalized quickly
in this situation, a most boring continuation that I refused out of hand. I
didn't check the king to swap a bishop for a knight.})

16. .. Kg8 17. Ng6 fxe5

(17. .. Nf5 18. Rad1 Nh6 19. Nxd5 exd5 20. Rxd5 Qc7 21. exf6 Bxf6 22.
Nxf8 Bg4 23. Qg6 Bf5 24. Qh5 Qf7 25. Qxf7+ Kxf7 26. Bc1 Kxf8 27. Bxh6 Bxc2
28. Bd2 {A violent variation from Houdini, something that you have to check
out because there is a lot to learn from it. However, the game did not go
that way at all.})

18. Qh8+ Kf7 19. Nxf8 {Here I publicly prove my idiocy.
The position before taking the rook was mate in 6 moves. As such, I got
cold feet at the apex of my attack. Just a few more seconds of thought and
I would have seen the continuation that the computer saw.}

(19. Nxe5+ Kf6
20. Qh4+ g5 21. Qh6+ Kf5 22. Qg6+ Kf4 23. g3# {A beautiful ending and
something that I should have seen. A pawn mate, with the king banished to
my side of the board and none of the Black pieces taken except three
pawns!})

19. .. Bxf8 {Now, my win in this game was almost completely the
merit of my opponent. I did wild and beautiful moves, but none of them were
actually accurate. At each point he could have come up on top, if he played
correctly.}

(19. .. Nf6 20. Rxe5 Qxf8 21. Qxf8+ Bxf8 22. Nxd5 Nf3+ 23. gxf3
exd5 24. Re3 {The computer would have quickly simplified the position and
taken advantage of its material gain. It would have made quick work of my
apparent king safety as well.})

20. Rxe5 Nf6 {I believe at this point Black
was considering cornering my queen. It would have required freeing the
rook, though, which was impossible.}

(20. .. Qf6 21. Re3 g6 22. Qh7+ Qg7
23. Qh4 Nf5

(23. .. Nxc2 24. Rf3+ Kg8 25. Nxd5 Qxb2 26. Rxf8+ Kxf8 27. Qe7+ Kg8 28. Qxe8+ Kh7 29. Qe7+ Kh6 30. Qh4+)

24. Rf3 Be7 25. Qf4 Bf6 26. Qb4 {A
long dance leading nowhere. My queen banished and the Black king
protected.})

21. Nxd5 {I saw this move that would have gained a pawn, freed
my rook and removed the only Black developed piece.} exd5

(21. .. Be7 22.
Qxd8 Bxd8 23. Nb4 Nf5 24. Nd3 {The computer would not have gone for it.})


22. Bxd4 Be6 23. Rae1 Bg4 24. Qh4 Qd7 25. h3 Bf5 26. R5e3 Nh7 27. Qh5+ {At
this point I was despondent. I had time trouble, my beautiful attack ended
in a big flop and the only thing I could think of was harassing Black's
pieces in an attempt to catch one off guard and gain the material
advantage.}

(27. Bxg7 Kxg7 (27. .. Bxg7 28. Re7+ Qxe7 29. Rxe7+ Kf8 30. Qb4
Bf6 31. Rxh7+ Kg8 32. Qxb7 Rf8 33. Rc7 Bg6 34. Qxa6)

28. Re7+ Qxe7

(28. .. Bxe7 29. Rxe7+ Qxe7 30. Qxe7+ Kg8 31. Qxb7 Rd8 32. Qxa6)

29. Rxe7+ Bxe7 30.
Qxe7+ Kg8 31. Qxb7 Rd8 32. Qxa6 Rd7 {The computer saw this continuation
which is pretty much forced. An interesting combo, but I doubt I could have
mated the king with only a queen against three pieces. I doubt I could have
won.}) 27. .. Kg8 28. Rf3 Bxc2 29. g4 {At this point I only had one idea
left: moving the g pawn front and use it to mate the king. It was as
transparent as it was desperate, but I think my opponent was completely
thrown off his game by the crazy maneuvres I had used.}

(29. Rc3 Be4 30. f3
Bf5 31. g4 {Houdini would also have pushed the g4 pawn, but with backup and
tempo. Again, something to be learned from that. Check out the wild
continuation it found.} Be6 32. Qe5 Re8 33. Rc7 {threatening the queen, but
also g7.} Bxg4 {completely crazy: this is a queen exchange, but the
computer saw the possibility to gain a pawn in the process.} 34. Rxd7 Rxe5
35. Rxg7+ {two can play that game. See how White is going for the pawns in
this insane position, as well.} Bxg7 36. Bxe5 Ng5 {Again, insane! Why not
move the bishop? because the knight can be developed and a new threat (f3)
can be declared.} 37. Kf2 Nxf3 38. Rd1 Nxe5 39. hxg4 Nxg4+ 40. Kf3 Ne5+ 41.
Ke2 Nc6 42. Rxd5 {White would not have won this, but was crazy game.})

29. .. b5 {His plan, to push his passed pawns and gain huge material advantage
or completely block my pieces from attacking would have worked, but it
needed some preparatory moves on the king side, which were not made.} 30.
g5 Be4 31. g6 {The bishop move came too late. I was threatening mate and
the only option to save the situation was the sacrifice of the bishop.}
Bxg6 32. Qxg6 b4 {Again, Black helps me out with a useless pawn move.} 33.
Re5 b3 34. Rxd5 {Enamored by wild moves I did this. The idea was that if
the queen was not defending g7, I could then take the f8 bishop with yet
another sacrifice and mate at g7. I completely missed that the rook could
be taken by the king, avoiding the mate.}

(34. Rh5 {Houdini went instead
for a safe mate in 7 which I missed, even if my initial plan was to move
the rook to h5, but I then forgot about it.} Ng5 35. Rxg5 Bd6 36. Qxg7+
Qxg7 37. Rxg7+ Kh8 38. Rf5 Bh2+ 39. Kxh2 a5 40. Rh5# {Another beautiful
computer mate.})

34. .. Qxd5 35. Rxf8+ Nxf8 {My always greedy opponent was
kind enough to not see the mate. I had time trouble and no matter the
material advantage, I had no time to finish the game without a blunder such
as this.}

(35. .. Kxf8 36. Qxg7+ Ke8 37. Qxh7 Rc8 38. Qh8+ Kd7 39. Qg7+ Kd6
40. Qg3+ Ke7 41. Qh4+ {The only solution for White was to check ad
infinitum, which was not possible if both sides played well. The game was
lost.})

36. Qxg7# 1-0

The game started as a whim. I wanted to do something, I didn't really feel like anything, so I started a chess game, expecting to lose. I am usually a fan of aggressive, off the book, starting positions so, when I was confronted by the Sicilian defence, I decided to try the Wing Gambit. Now, I know I wrote a blog entry about it, but I did not remember anything from it and it would have been unfair to read the blog entry while playing, so I went with the first three moves and then winged it (get it?).

I want to thank Black for helping me along, as with the silly moves I did it was impossible to win if it weren't for his valuable assistance >:)

There are comments in the game as long as several variations. What I want you to pay special attention to is the variation at move 19. If I would had seen it, and I should have had, the game would have been over in a spectacular fashion in only 25 moves. Other variations show how the game could have ended if Black has played well.

Enjoy!

After such a long pause it seems only natural that I come up with a good chess blog post and I think this one, about the Evans Gambit, fits the bill. Since it is a gambit employed in the Giuoco Piano/Italian Game opening, it has been widely used from the 1820s when it was first documented. There are numerous videos on it on YouTube, but the one I consider the best is the one below, from GM Gregory Kaidanov.



I have also explored the gambit with ChessBase, but there it is difficult to see the spectacular games, the ones that lead in traps or quick wins, as they are often studied and the mistakes there not repeated in high level games.

1. e4 e5
2. Nf3 Nc6
3. Bc4 {The Ruy-Lopez (Bb6) is twice as common, but this is the second most popular move for White.} Bc5 {The main Black response to Bc4, almost on par with Nf6.}
4. b4 {The Evans Gambit, giving material for speed. It is interesting to note that this gambit is the second most popular way to go from here, after the mainline c3.}
(4. O-O {When first invented by Evans, he castled first.} d6 {Here is a trap in the original Evans Gambit.}
5. b4 Bxb4
6. c3 Ba5
7. d4 Bg4
8. Qb3 Qd7
9. Ng5 Nd8
10. dxe5 dxe5
11. Ba3 Nh6
12. f3 Bb6+
13. Kh1 Bh5
14. Rd1 Qc8
15. Rxd8+ Qxd8
16. Nxf7 Bxf7
(16... Nxf7
17. Bb5+ c6
18. Qe6+ Qe7
19. Qxe7#)
(16... Qh4
17. Bb5+ c6
18. Qe6+ Qe7
19. Qxe7#)
17. Bxf7+ Nxf7
18. Qe6+ Qe7
19. Qxe7#)
4... Bxb4 {The overwhelmingly more used move to accept the gambit, rather than decline it.}
(4... Bb6 {A possible run for the lot less employed gambit declined variation.}
5. a4 a6 6. Nc3
(6. a5 Ba7
7. b5 axb5
8. Bxb5 {This transposes into a sort of Ruy-Lopez.})
6... Nf6
7. Nd5 Nxd5
8. exd5 Nd4
9. a5 Ba7
10. d6 cxd6
11. c3 Nc6
12. O-O O-O
13. d4 h6
14. Re1 Qf6
15. Nd2 exd4
16. Ne4 Qg6
17. cxd4 d5
18. Bxd5 Nxb4
19. Bb3 d5
20. Ng3 Bg4
21. Qd2 Nc6
22. Bc2 Qf6
23. Qd3 g6
24. Bxh6 Bxd4
25. Bxf8 Rxf8 {0-1 Santos,M (2245)-Martins,C (2278)/Americana 2000/EXT 2001})
5. c3 {Multipurpose move to defend d4, make way for the queen to go to b3 and doing it with tempo as it is attacking the Black bishop.} Ba5 {Bishop retreats, keeping an eye on the White king.}
(5... Bc5 {Bc5 transposes easily, but also has the disadvantage of giving White an extra tempo after d4.}
6. d4 exd4
7. O-O)
(5... Be7
6. d4 Na5
7. Nxe5 Nxc4
8. Nxc4 {Beautiful center and development options.} d5
9. exd5 Qxd5
10. Ne3 Qd8
(10... Qa5
11. O-O Nf6
12. c4 O-O
13. Bb2)
11. O-O Nf6
12. c4 O-O
13. Nc3)
(5... Bd6 {Not used a lot, as it cramps the d pawn.}
6. d4 Nf6
7. O-O O-O
8. Re1 h6
9. Nbd2 {Leads for a closed game for both sides, not really in the Evans spirit.})
6. d4 {Defended by queen, knight and a pawn that is, at the moment, pinned, White aggressively makes a claim on the center.} exd4 {The defending pawn can not move and taking with the knight invites a host of unpleasantness}
(6... d6
7. Qb3 Qd7
8. dxe5 Bb6
9. Nbd2 Na5
10. Qc2 Nxc4
11. Nxc4 d5
12. exd5 Qxd5
13. Qa4+ Bd7
14. Nxb6 cxb6
15. Qb4 Ne7 {Three games in the database for this, two White wins and a draw.})
(6... Qe7
7. O-O Bb6
8. Ba3 d6
9. Bb5 Bd7
10. Bxc6 Bxc6
11. Nxe5 Bb5
12. Re1 Qe6
13. Nf3 O-O-O
14. Bb2 a5
15. Nbd2 Qd7
16. c4 Ba4
17. Nb3 Ne7
18. Qd2 Nc6
19. Bc3 Rhe8
20. d5 Nb4
21. Bxb4 axb4
22. Qxb4 Bxb3
23. axb3 {1-0 Sveshnikov,E (2560)-Sofieva,A (2370)/ Cappelle la Grande 1995/EXT 1997})
(6... Qf6
7. O-O Nge7
8. Bg5 Qd6
9. d5 Nd8
10. Qa4 b6
(10... f6
11. Bc1 Bb6
12. Na3 c6
13. Rd1 {Tchigorin})
11. Na3 a6 {Two games between Chigorin and Steinitz in 1889 from here: one won by White, the other by Black.})
7. O-O {Main themes in the Evans: keep your king safe, develop as many pieces as possible and prevent the Black king from castling.} Nge7 {Nge7 is the move masters have found most effective against the Evans gambit, as well as d6, but at amateur or club level it is more likely you will see Black take the pawn on c3.}
(7... d6 {Meant to protect against the push of the White pawn to e5 and liberating the bishop.}
8. cxd4 Bb6
9. Nc3
(9. d5 Na5
10. Bb2 Ne7 {And again: Nge7.}
11. Bd3 O-O {At this point we can assume that the gambit has failed, as Black has achieved castling, but they are not out of the woods yet.})
9... Bg4 {Black is planning to castle queen side and their position is getting better.}
(9... Nge7 {At this point, Nge7 is a mistake.}
10. Ng5 O-O
11. Qh5)
(9... Nf6
10. e5 dxe5
11. Ba3 {Not taking the e pawn, but preventing Black from castling!} Bxd4 {let us see how it could go down from here.}
12. Qb3 Qd7
13. Rae1 Na5
14. Nxe5 Nxb3
15. Nxf7+ Qe6
16. Bxe6 Bxe6
17. Nxh8 {White wins a lot of material here.})
10. Bb5 Bxf3
11. gxf3 {Take with the pawn to continue to protect d4.} a6
12. Ba4 Ba5
13. Bxc6+ bxc6
14. Qa4 Bxc3
15. Qxc6+ Kf8
16. Qxc3 {Now material is even, but Black cannot castle and does not control the center.})
(7... dxc3 {Taking the pawn, accepting this second gambit, might seem a good idea, but it only allows White to develop a powerful attack.}
8. Qb3 {attacking e7, b7, c3 as well as getting close to the lightly defended Black bishop.} Qf6 {The only options for Black to defend the e7 pawn are Qf6 or Qe7.}
(8... Qe7
9. Nxc3 Bxc3
(9... Nf6 {The usual move in this situation is Bxc3. The Nf6 variation is what happened in the Fischer-Fine game from 1963, the one in the video above. The rest of the moves are from that game.}
10. Nd5 Nxd5
11. exd5 Ne5
12. Nxe5 Qxe5
13. Bb2 Qg5
14. h4 Qxh4
15. Bxg7 Rg8
16. Rfe1+ Kd8
17. Qg3 Qxg3
18. Bf6#)
10. Qxc3 f6 {At this point Black has not yet achieved safety, but it is pretty close. I continue with the main line, without annotations.}
11. Ba3 d6
12. Bd5 Bd7
(12... Qd7
13. Rac1 Nge7
14. Rfe1 Qd8
15. Nh4 Bg4
16. Qg3 Qd7
17. h3 Be6 {Rajaboz-Smeets 1995, ended in draw.})
13. Rfe1 O-O-O {Black castles (Steinitz Gray 1872), although White manages to win.})
9. e5 {The pawn cannot be taken due to the threat of Re1.} Qg6 {Only good square for the queen.}
(9... Nxe5
10. Re1 d6
11. Qb5+ {and if Black protects the knight with the pawn on d7, they open themselves to this fork.})
10. Nxc3 {Gaining back a pawn and bringing yet another piece into the game. White has brought almost all the pieces out, while Black is cramped.} Nge7 {And here it is again, Ne7. If playing correctly, it seems Black cannot move that knight anywhere else in any variation.}
11. Ne2 {Very sophisticated idea, as it attempts to lure Black into castling and losing their queen or some other piece in its attempted rescue.} O-O {Black falls into the trap. The next few moves demonstrate it.}
12. Nf4 Qe4 {The only acceptable move for the queen.}
(12... Qg4
13. h3 Qf5
14. Bd3 Nd4
15. Nxd4 Qxe5)
(12... Qh6
13. Ne6)
13. Bd3 Qb4 {Only safe square.}
14. Qd1 {The Black queen is still in trouble, as Rb1 follows.} Ng6 {This is the only move that is giving respite to the queen, but White still gains advantage.}
(14... d6
15. Rb1 Qc5
16. Rb5 Qc3
17. Bb2 {Queen is trapped.})
15. Rb1 Qe7
16. Nd5 Qe6
17. Rb5 {threatening to take on a5 and then fork queen and rook at c7.} Rb8
18. Ba3 d6
19. exd6 cxd6
20. Ng5 Qd7
21. Qh5 h6
22. Nf6+ gxf6
23. Qxh6 fxg5
24. Bb2 Nce5
25. Rxe5 dxe5
26. Bxe5 f6
27. Bc4+ Rf7
28. Qxg6+ Kf8
29. Bd6+ Ke8
30. Qg8+ Rf8
31. Qxf8#)

For more background you can scour the net for videos on the Evans Gambit, there are a lot. There are a multitude of traps in the Evans as well, for the unprepared. One video that I do recommend, though, is Ruy Lopez vs Italian Game where it is explained why the Giuoco Piano is less favoured than the Ruy Lopez, even if it seems to open up more avenues of attack, and also what are the goals of White in the opening, thus explaining a lot about the coices made during the Evans Gambit.

Enjoy!

Any person that is remotely interested in the history of chess knows the name of José Raúl Capablanca. He was a great chess player and the world champion for 7 years in a row. I've just finished reading one of his books, entitled Chess Fundamentals, and I thought it was great. It featured clear chess principles, backed by real master games and, what I believe it is most important in the book, all the matches featured in Chess Fundamentals are annotated by Capablanca, who focuses on what moves he saw best, the ones he didn't like and, most fortuitous, what he thought when he played those moves, as many of the games are his.

Unfortunately, as with any chess book, one must spend time to focus on the details and to revisit it as many times as it takes to understand and learn what Capablanca wanted to express. I've read the book as part of an iPad application called "e+books". You get the free application, this Capablanca free book, then you have to pay for any other there. What I found really nice is that the positions and moves in the book are mirrored by a chess board that allows navigation between moves, variations, going back and forth, etc. It really helps reading the book and I recommend it, especially for beginners. Using a real chessboard to mirror the moves might be best, but it adds a layer of discomfort and complexity that might deter someone from finishing the book.

The book is structured into 6 chapters, the last being a series of 14 games in which Capablanca either lost or won. He begins with some principles of the endgame, the part of a game that he considers the most important. If you recall, Josh Waitzkin also highly recommended focusing chess training on the endgame, where there are few pieces and the principles become clearer. Also, since some chess games end with mates somewhere in the middle game, there is less opportunity to learn that part of chess. For openings Capablanca has only a few words, focusing on the healthy development of pieces, which he considers the most important. As stated previously, the games are the most important and their complexity is pretty high. Some say that the book is not fit for beginners for that reason alone, but I disagree. Even the most complex strategies are explained in the annotations and I believe they are a rare opportunity for anyone to glimpse in the mind of a chess master and realize where their aim as chess players lies.

All in all a rather easy to read book, with the help of the iPad application, but very hard to completely understand and remember. I intend to return to it, several times perhaps, in order to internalize some of the cool patterns of thought I saw in there. I warmly recommend it.

I have seen there is a marked difference between me, a casual chess player that has become interested in the theory of chess, and other people of my level that do not try to understand the theory. I usually beat them with the help of some of the information that lingers in my head. At the same time, there is an even greater difference between me and people that actively play chess online, not only when a colleague becomes interested in playing. They crush me immediately.

It seems to me that in order to grasp the chess theory I must also back it up with practice. So I have decided (after quite a while of fearing it would either become addictive or that I would suck terribly) I've made the first step and played a game there. And I won! Woo hoo! Unfortunately I played horribly and only luck can be attributed to my victory. As always, I've analysed the PGN and here it is. You will understand the shame of my victory (yes, it can happen) when you get to the end. Enjoy!

[Event "Siderite vs Mar09 2012.07.14"]
[Site "Chess.com"]
[Date "2012.07.14"]
[Round "1"]
[White "Siderite"]
[Black "Mar09"]
[Result "1-0"]
[BlackElo "2400"]
[ECO "C41"]
[Opening "Philidor"]
[Variation "Hanham, Steiner Variation"]
[WhiteElo "2400"]
[TimeControl "0+300"]
[Termination "normal"]
[PlyCount "77"]
[WhiteType "human"]
[BlackType "human"]

1. e4 {+0.11/16 10} e5 {-0.09/16 10} 2. Nf3 {+0.13/15 10} d6 {-0.31/15 10}
3. h3 {+0.15/15 10} Be7 {-0.15/15 10} 4. d4 {+0.16/16 10 Didn't know
anything about the Philidor defence that Black employed, except that it is
rather passive. So I decide to attack.} Nd7 {-0.26/15 10} 5. dxe5 {+0.26/16
10} Nxe5 {-0.24/16 10} 6. Nxe5 {+0.23/17 10} dxe5 {-0.23/17 10} 7. Qxd8+
{+0.23/17 10} Bxd8 {-0.15/17 10} 8. Bc4 {+0.04/17 10 computer thinks that
defending the pawn with the knight would have been better. As such, Black
has equality.} Ne7 {-0.23/16 10} 9. O-O {+0.27/16 10} O-O {-0.26/17 10} 10.
Nd2 {+0.20/18 10} Kh8 {-0.38/16 10 Analysis says this is a bad move and
gives White 0.2 because the pawn at f7 is defended only by the rook, but
Black intends to move it forward anyway.} 11. Nf3 {+0.35/16 10} f6
{-0.30/16 10} 12. Bd2 {+0.27/17 10 at this moment I am lost: I have no
strategy, no obvious attack and so I decide to improve my position a little
bit.} a6 {-0.28/15 10} 13. Bb4 {+0.24/17 10} b5 {-0.88/17 10 I thought
about the computer suggested move at the time: Bc4-d5, but dismissed it
because I felt it did not do anything.} 14. Bb3 {+0.46/17 10} a5 {-0.48/18
10 I almost always fall for pawn pushes. I tend to dismiss their
importance, you see, until it is too late.} 15. Bc5 {+0.48/19 10} a4
{-0.57/18 10} 16. Bd5 {+0.71/17 10 Bd5 is no longer as effective as it
would have been.} Ra6 {-0.54/17 10} 17. a3 {+0.54/19 10 The only move to
save my poor light bishop from getting trapped after c6.} c6 {-0.86/19 10}
18. Ba2 {+0.88/19 10} h6 {-1.97/17 10 You see what I should have done here?
Ra1-d1 would have threatened the bishop on d8, the only defender of the
pinned knight on e7.} 19. c4 {+0.59/17 10 Instead I tried to exchange a
weak pawn with a strong one, breaking the menacing pawn chain c6, b5, a4}
(19. Rad1 Kh7 20. Rxd8 Rxd8 21. Bxe7 Rd7) 19. .. Re8 {-0.72/18 10} 20. Rad1
{+0.43/18 10} Ng6 {-5.97/17 10 too late for Rd1, but do you see the winning
move for White here?} 21. g3 {+0.33/17 10 instead I get spooked by the
knight and try to block it and leaving my h3 pawn undefended.} (21. cxb5
cxb5 22. Bf7 {nice pin, one might think, but look closer: the rook at e8
has nowhere to go, the bishop on d8 is defended by the rook alone and the
knight on g6 is also under attack. This gives White a staggering 6 point
advantage.} Rg8 23. Bxg8 Ba5 24. Bf7 Nf4 25. Be8 {b5: completely
undefendable} Ne6 26. Be3 b4 27. Bb5 Ra8 28. Bc6 Ra6 29. Rc1 bxa3 30. bxa3
Nf4 31. Bxf4 exf4 32. Rfd1 Be6 33. Bxa4 Ra8 34. Bc6 Ra7) 21. .. Bb6
{-2.12/18 10 at this moment I still had the trap for the rook on e8, but it
was invisible to me.} 22. Bxb6 {+0.22/17 10} (22. cxb5 Bxc5 {this is the
best move in the situation} (22. .. cxb5 23. Bxb6 Bxh3 24. Rfe1 Rxb6 25.
Bf7 Reb8 26. Bxg6 {White has more than 2 points advantage here.}) 23. bxa6)
22. .. Rxb6 {-0.17/18 10} 23. Kh2 {-0.05/18 10 Yay, I saved the pawn!, I
thought at the moment... by doing so I have missed every opportunity and
reached equality with Black.} c5 {-0.38/17 10} 24. Rd5 {-0.15/17 10} Bb7
{+0.14/18 10} 25. Rxc5 {-0.17/19 10} Bxe4 {-0.07/18 10} 26. Nd2 {+0.09/19
10} Bd3 {-0.11/18 10} 27. Re1 {-0.04/17 10 the computer advises to take the
soon to be open c file. I miss that, too. Little did I know what incredible
edge it would give me at the end. Goooo, luck!} b4 {0.00/16 10} 28. Re3
{-0.07/16 10} Bc2 {+0.13/16 10 again, I decided to play aggressively. If I
could exchange the rooks, I would have a powerful passed pawn.} 29. Rb5
{-0.41/18 10} Rd6 {+0.45/19 10} 30. Ne4 {-1.51/16 10} Bxe4 {+1.64/17 10}
31. Rxe4 {-1.55/19 10} b3 {+1.62/17 10} 32. Bb1 {-2.36/16 10 my light
bishop is trapped. All one has to do is move the rook on d1.} Rd2 {+0.83/19
10 fortunately Black misses it.} 33. c5 {-2.11/17 10 and I ignore that f2
is undefended and, more, it would place me in check.} Rxf2+ {+2.10/19 10}
34. Kg1 {-2.13/20 10} Rxb2 {+2.19/20 10} 35. Re1 {-2.24/19 10 the situation
is dire. Black has 2 pawns ahead and if he sees that I attacked his knight
with the bishop while defending it with the rook, I am a goner.} Ne7
{+2.36/18 10} 36. Rb4 {-2.40/18 10} Nc6 {+1.73/15 10} 37. Rxa4 {-2.18/16
10} Nd4 {0.00/18 10 He saw the knight being attacked, but didn't notice the
pawn on e5 is pinned. It is not all lost for Black, since after a few
exchanges we reach equality. But check out the next moves!} 38. Rxd4
{+0.03/19 10} exd4 {-M1/69 10} (38. .. Rxb1 39. Rxb1 exd4 40. Rxb3
{complete equality and probably a loss for me, as I don't know much about
endgames.}) 39. Rxe8# {Yup. Mate. Neither of us has seen it. When I took
the rook I thought he resigned, as the game ended so suddenly. But no, it
was an accidental mate. How embarrassing.} 1-0