Saturday, September 29, 2007

Coffeehouse nuggets

I have a few nuggets that I remember from today's trip to the coffeehouse.

The first position arises from a French defense. I don't usually play 1. e4, but decided what the heck, I'll play it today. I thought we were in an interminable positional struggle where my opponent had a bad bishop and couldn't really break my position. I have good knights, but I don't really see what targets they can hit.
White to move

The knight on f4 holds my kingside and influences the center. I'm planning to play on the c-file and try to get my other knight to d6 or c5, though I'm not even sure what my targets are from there. All that becomes moot when my opponent drops Rhd8 in my lap.

In the next example, I think I was very close to getting run over in an opposite side castling game. I caught a break when my opponent overlooked my only tactical chance.
Black to move
(I just realized, the king should be on c8, not b8 -- will fix the diagram later)

This one obviously takes some deeper calculation, but I've been thinking about the first move of this combination for most of the game so a lot of the lines seemed to come naturally. For a Temposchlucker plan beta hint -- the first invasion square is f2, the second invasion square is h3.

The game continued 1. ... Ng4+ 2. Kg1 Bxf2+ 3. Kh1 h4 4. Be3 hxg3 5. b5 Qh5 6. Bxf2 Nxf2+ 6. Rxf2 Rxf2 7. Nxd6+ Kd7 8. Nxb7 Rxg2 9. bxc6+ Ke7 10. Qa3+Ke8 11. Kxg2 Qxh3+ 12. Kf3 Qf5+ White resigns.

I believe there are improvements for both sides in that line, but I don't think there is a refutation of black's play. It's a real exercise to calculate all the possibilities and I certainly didn't do that over the board.



Ct-Art update, 94% on level 30. 178 problems done out of 221. Looks like I'm going to have a huge improvement on 86% three times in a row.

Update: Finished level 30, rep 4 today. 92%! Ok, I slipped up a bit at the end, but it's still a big deal to do this much better. I'll go back and review the last 20-30 problems of the level before I move on to level 40.

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Tuesday, September 25, 2007

Overseen

Here is a position overseen at the coffeehouse. The tactics in it were overlooked by the players. Ok, the position here is subject to my memory, but the basic tactic is there.

Black to move

Here black didn't quite find the winning idea Be6 Ng5 Re1+ Kh2 Bd6 pinning the rook. (sideline: Be6 Rc4 Re1+ Kh2 Bg1+ Kg3 Bxf7)

Thanks to everyone who has encouraged me in my tactics training. I'm about halfway through level 30 at 95%. Knock on wood, but I think I'll beat my old 86% score for this level.

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Tuesday, September 18, 2007

Level 20, rep 4

I finished level 20 rep 4. Significantly faster than last time through and at a higher percentage -- 98% (up from 92%, 94%, 95%). On to the real test of level 30, the real thorn in my side. I'm out of town Thursday to Monday which will slow me down a little. That's life, no wonder I can't do it the same as DLM.

Some concrete things I wrote down this time through:
-- Exercises 145 and 352 are the same
-- Exercises 217 and 228 are the same

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Saturday, September 15, 2007

Improvement!

I've just completed my 3rd repetition of level 40 of CT-Art and finally I have seen a significant improvement in my solving percentage.
Level    Rep 1   Rep 2   Rep 3
-------------------------------
10 97% 99% 99%
20 92% 94% 95%
30 86% 86% 86%
40 77% 77% 84%

That is a major improvement on level 40 problems. This isn't from memorizing the problems, I am really calculating better on this level. Incidentally, I also noticed a couple more problems with secondary solutions. Maybe next time through I'll start recording all these.

It is now 20 days since I last restarted on level 10. So according to my 3 week schedule, I'll start back at level 10 rather than move up to level 50. I think my last "3 weeks" to do levels 10 through 40 was actually 22 days. So I am only slightly faster -- though over the last 3 weeks I've spent time playing more games and analyzing them, so I'm not too concerned. I think I'll be much faster over the next 3 weeks.

Update: I just did level 10 for a fourth rep. Finally a perfect score, no mistakes! It took me just under 40 minutes to do the 110 problems of level 10.

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Monday, September 10, 2007

Chess Life History

A hat tip to Castling Queenside for posting about a program that will strip out nifty data from your MSA record at USCF. It's a nice trip down memory lane, and I like the graph feature. I recall seeing a similar utility for making ratings graphs a while back, I think it might have been a Flash plugin.

Saturday, September 08, 2007

A swindle and another BOOC ending

I had some interesting positions from the coffeehouse this week.

Here is one from a game I was losing. It was a complicated middle game where we both had chances. My opponent sacked the exchange and got a couple pawns for it. We pick up a position where I'm barely hanging on, trying to harrass my opponents two minor pieces to keep him from making progress. Then I spot a swindle:

Black to move

After Rg7+, black blunders with Kh4?. Checkmate follows in two moves.

I also wound up in another bishops of opposite color endgame. I believe this is not just a simple draw because of the presence of the rooks. Here is one interesting point.

Black to move


There must be something I am mis-remembering about this position since Ra8 just hangs the rook to Bxa8 -- For now I imagine the rook might have been on b6.

The white king is approaching black's passed pawns. Black wants to keep the king away and at the same time try to penetrate and attack white's kingside pawns. Unfortunately, the rook is tied down to the defense of the b-pawn. Since b4 allows Kc4, black has to find Ra8! where the response Rxb5 is met by Ra3+ Ke2 (Ke4 Re3#) Ra2+ Kf1 Rf2+ followed by taking the bishop or a discovered check to win the rook.


We pick up the game a little later. Black was able to bring the rook around and win the a2 pawn. Now black threatens the b3 pawn. White has found a way to defend it twice.

Black to move

Here I chose a simplifying sacrifice. Bxg3+ Rxg3 Rxg3 Kxg3 b3 and white doesn't have the resources to stop so many pawns. Notice that even the h and f pawns protect each other with a classic trick of two pawns separated by one file against a king. If Kh4 f4 then white can't play Kxh5 because the f-pawn will promote. So the bishop is tied to the b-pawn promotion square and the king is tied to the h-pawn which it cannot attack. The black king is free to do whatever black likes, take the e-pawn, help support the c and b pawns or the e and f pawns.

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Friday, September 07, 2007

level 30, rep 3 -- I still stink

I've finished level 30 for the 3rd time. And for the 3rd time I've scored an 86%.

Of course, this is very disappointing for me. I'm not going to change my current plan just yet. I have a little over a week before I start over again at level 10. I'd like to give that idea more time.

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Tuesday, September 04, 2007

My loss to the Budapest

One of my games at the coffeehouse last weekend was against the Budapest. This is a gambit for black that starts 1. d4 Nf6 2. c4 e5 3. dxe5 Ng4. I don't like letting black have all the initiative, so I play a line that gives the pawn back. I have a feeling I'll be seeing the Budapest on a regular basis from this opponent, so if anyone has comments on any line of the Budapest, I'd be happy to hear it.

I posted the whole game at chesslog. I'll say a little more about two positions here.

After the opening moves, 4. Bf4 Nc6 5. Nf3 Bb4+ 6. Nbd2 Qe7 7. a3 Ngxe5 8. Nxe5 Nxe5 9. e3 Bxd2+ 10. Qxd2 O-O 11. Be2 d6 12. O-O b6

White to move

Black has just played b6, no doubt to put his bishop on the long diagonal. I tried for a while to calculate something that would take advantage of the open diagonal before the bishop develops. The immediate Qd5 is met by c6. Bxe5 Qxe5 Bf3 doesn't get anywhere after Rb8.

Instead I settled on trying for a kind of minority attack. If I can break down the queenside pawns, black will be saddled with a weak, attackable structure. The game continued 13. b4 Bb7 14. Rab1 Rad8 15. Qc3 Qf6 16. Bxe5 dxe5 17. c5 h5 18. b5

White to move

I'm keeping with my plan of breaking down the queenside pawns. Unfortunately, I've underestimated the attacking that's coming on my king. I also misplay the defense pretty badly. 18. ... bxc5 19. Qxc5 Qg6 Black lets his third pawn hang without protection, it's as if my plans are working. Until, 20. f3 Rd2 21. Qc4?? This should have been immediately punished by Bd5. Black still won with 21. ... e4 22. f4 Bd5 23. Qc5 Rxe2 24. g3 Be6 25. f5 Qg5 0-1

It's important to take care of your house before you steal from your neighbors garden.

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Sunday, September 02, 2007

Two endgames

I have a couple of endgame positions from recent games at the local coffeehouse. There is no doubt the importance of the endgame. It's also true that the endgame is so rich, you'll never run out of interesting things to study there. Exhibit A is likesforests who has had numerous very good blog posts on the endgame.

Position 1, a win with bishops of opposite colors!

White to move

This game could easily have been drawn until Black made two mistakes to lose it. The first, is losing a pawn of f6 so that white's f-pawn is now a passed pawn. The second is becoming too aggressive with the king. If the king were back to stop the f-pawn, the game would still be drawn. Now white wins with Be5 and f5. Black must play Bc3 to stop the pawn allowing white to take on e4 and support the f-pawn with the king, eventually winning black's bishop and g-pawn.

The second position is a king and pawn endgame that features a combination of interesting techniques.

White to move

White has to be able to envision that this position is winning (or at least drawn) before entering into it. Black has a passed pawn on the a-file so white's king is tied down to stopping that threat. In the meantime, how does white stop black from marching into e4 and taking the e3 pawn?

The answer is a kind of breakthrough. If the black king ever comes to e4, white wins by playing b5! where black cannot stop a pawn from queening, e.g. cxb5 c6 or Kd5 b6. So now we realize that e4 is forever off limits to the black king due to this breakthrough. This means that in the diagrammed position white can play Kb2! and go take the a4 pawn without fear of losing since black can make no progress.

The question then is whether or not this will win or draw for white after Kb2! Kd5 Ka3 Kc4 Kxa4 Kd5:

White to move

Now white's plan is to go after the a-pawn. Let's look at the direct route: Ka5 Kc4 and now if Ka6 Kxb4 is not good for white. Note that if the pawn is on a6 instead of a7, Kxa6 Kxb4 Kb6 wins for white. This means that black can never advance the a-pawn to a6. As a result, black will forever be doing a king shuffle on c4, d5, and e6. And, in order to stop white's plan, the king must move to c4 when white plays Ka5. Since he can only get there from d5, the black king can be triangulated. Kb3! Ke6 Ka3! Kd5 Ka4 Kc4 Ka5 Kd5 Ka6 Kc4 Kxa7 Kxb4 Kb6 wins the b-pawn and leads to promotion.

Final caveat. When white has his king on a4, the pawn break doesn't work because after b5, cxb5+ is check. So if black plays Ke4 while the white king is on a4, white plays Ka5. Then Kxe3 is met by the breakthrough and Kd5 is met by Ka6.

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