Thursday, November 20, 2008

iPod Touch Chess Applications?

I scored an iPod Touch for my birthday. I saw that there are several chess apps available, but I get the impression that the reviews are grossly padded by developer sockpuppets.

Anyone have iPod/iPhone chess apps that they particulary like? I noticed that at least one (Caissa Chess) mentions playing by email. This is of some interest, since I'm currently playing a pair of email games with someone from the club.

Tuesday, November 18, 2008

Rybka 3 Arrived, but...

My birthday gift to myself arrived...Deep Rybka 3 with the ChessBase interface. Unfortunately, one of the features I was most interested in--Monte Carlo analysis-- isn't working. Shortly after starting the analysis, the program crashes.

I just contacted ChessBase support. Hopefully the issue will be resolved in time for my birthday! I'm curous, though, if other readers have had a similar problem and know a solution.

Saturday, November 15, 2008

Simple Forcing Variation

The following tactic is fairly easy to calculate, yet it gave me some trouble. I'm finding that, when calculating forced variations, I have more difficulty when I have a choice of moves than when my opponent has a choice of moves.

White to play:

4r1k1/ppn1bppp/q7/7Q/1nN1P3/1B1P4/PP5P/KN4R1 w - - 0 1

Black to play has a straightforward mate in 2 starting with 1...Qxa2+, so White's play either has to interfere with this mechanism, or be with check. Moves like 1.Nca3 or 1.Na5 don't lead to anything. That leaves two checks: 1.Rxg7+ or 1.Qxf7+. The former check doesn't seem to lead anywhere either (e.g. 1...Kxg7 2.Qg4+ Qg6).

1.Qxf7+ looks like an "obvious" queen sac, because after 1...Kxf6 the knight can move to e5 or d6 with a discovered, double, check. But which knight move?

Correct is 2.Ne5+, because on either 2...Kf6 or 2...Kf8, 3.Nd7#.

However, when I tried to calculate this as I would in an over-the-board game, I would stall at this point. I was seeing the king slipping out of the mating net with 2.Nd7, and didn't immediately see the mate after 2.Ne5 Kf6. That was enough for me to second-guess the entire line and try to find ways to get other first moves to work. In a real game I probably would have bailed out by playing a knight to a3.

This demonstrates both quiescence errors (not calculating out until all checks, captures and threats are spent) and not "thinking like a tree" a la Kotov (calculate each branch of each line only once). And yes, Kotov's technique has been criticized by others, but in general (especially for simple problems like this one) it's an ideal worth striving for.

Tuesday, November 11, 2008

Euwe Blunder

The next time you feel bummed out because you made some patzer oversight, remember the following blunder that Euwe played against Lasker in the Nottingham 1936 tournament:

8/pp4pp/2p1kp2/b7/2nP4/3K3P/PP3PP1/2B1N3 w - - 0 24

Euwe (Black) had just played 23...Bc7-a5, attacking the knight on e1. If White captures on c4, Black captures on e1. If white moves the e1-knight, Black moves their threatened c4-knight.

But what if White could move the knight with threat?

24.b4! Bxb4 25.Nc2! and Black is going to lose a piece. Euwe chose 25...Bd2 26.Bxd2 Nb2+ 27.Ke2 and resigned six moves later.

Tuesday, November 4, 2008

Capablanca Making It Look Easy

I've been working on Alekhine's tournament books for NY 1924 and Nottingham 1936. I've finished the first, but am still adding the annotations to my "Master Games" database (a real pain, because all the annotations are footnotes, so there's a lot of page flipping involved). I'm about halfway through the Nottingham book.

I keep finding that it's the little details that I find the most interesting. I don't retain much about the games as a whole, even if it won a brilliancy prize. Yet Alekhine can mention in a footnote "This move loses a tempo", and I can appreciate how such minor inaccuracies can lead towards a loss.

Similarly, I'm once again impressed by the elegance of Capablanca's endgames, especially against weaker players. One of my favorite chess books was Capablanca's Best Chess Endings by Chernev. If there is one player's style I would most like to emulate, it's Capablanca's ability to accumulate advantages and then win the endgame. A lot of the moves in these endgames feel natural, or even simple.

Here is a snippet from the game Thomas-Capablanca, Nottingham 1936, after White's 25. a4?

White's last move has weakened the b-pawn, and Capablanca proceeds to nail it down as a weakness:

25...Bxd4 My instinct would have been to retain the bishop, because there will be play on both sides of the board. Fritz seems to want to keep the bishop as well. 26. Rxd4

Alekhine gives 26.cxd4 Re1 27. Kg2 Rxf1 28. Kxf1 Ke7 29. Rc3 Kd6 30. Rc5 Rb8 31. Ra5 Rb6, which completely ties White up.

I looked briefly at 27. Rxe1 (instead of Alekhine's 27.Kg2) 27... Rxe1+ 28. Kg2 Rc1 29. Re3, where the white rook cuts off the king from running to the queenside. However, Black's majority is on the kingside and it looks like Black can work on both sides of the board towards a win.

Now, however, Capablanca's crisp play nails down the new weakness:

26... c5 27. Rd2 Rb8 28. Rb1 a5

The b-pawn is a fixed weakness, whereas Black's e-pawn isn't really weak. The king will move towards the queenside and help protect it. Black's king is then well placed in the center, whereas White's king is off to the side keeping an eye on Black's majority.

Capablanca concluded by playing on both sides of the board, using both his majority on the kingside and White's weaknesses on the queenside. The game concluded: 29.Kg2 Ke6 30. Rc2 Kd6 31. f3 g5 32. Kg3 h5 33. h4 gxh4+ 34. Kxh4 Re3 35. Kg3 c4 36. b4 axb4 37. cxb4 Rb3 0-1

The "simple idea" here for me was fixing the backwards b-pawn as a weakness. However, we can see a number of other classic themes in this example: mobilization of a pawn majority; play on both sides of the board and the principle of two weaknesses; centralizing the king; control of an open file.