Published on June 14th, 2009

I have upgraded to WordPress 2.8, but it seems that this resulted in some problems with the chess diagrams and replayable games.
I’m trying to solve this.

Update: The problem has been solved.
I had to adapt the Show-FEN plugin. A new version of the Show-FEN plugin v1.4 can be downloaded here.

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Published on May 19th, 2009

The following diagram is a nice exercise about a chess position that looks rather easy at first sight. It’s White turn to move. Is this a draw?








White to move
Position after move 0
0 half-moves after last pawn advance or capture

It’s White’s turn to move, but Black will gain a tempo because of the check by f4+. So at first sight it may look like a draw, but as we will see White will be able to win this game.

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Published on February 27th, 2009

In the game Colle – O’Hanlon, Nice 1930 we have seen one of the most famous examples of the Classical Bishop Sacrifice. In this lesson we will focus on some of the aspects of such a position that will help you to determine whether or not the sacrifice will be sound. I am going to use the game Kothe Harry G – Lewis James W, 1974 as an example.

 








White to move

Classical

1.d4 d5 2.c4 dxc4 3.Nf3 e6 4.e4 b5 5.a4 c6 6.Bd2 a5 7.axb5 cxb5 8.b3 Bb7 9.bxc4 b4 10.Bd3 Bd6 11.Be3 Ne7 12.O-O O-O 13.e5 Bc7

The main conditions for the sacrifice are met:
- A bishop is able to capture the pawn on h7
- A knight is able to move to the g5 square
- This g5 square is defended
- The queen can reach h5

We even have some additional conditions that make it more likely that the sacrifice will be correct:
- Black’s Queen on d8
- Black’s Rook on f8
- White’s pawn on e5 will prevent an escape to f6

But there is also an indication that the sacrifice will not be sound:
- Black’s bishop on b7 may be able to defend h7

As we will see the sacrifice will be sound. Black’s bishop is rather harmless and will be attacked and undefended on e4.

14.Bxh7+ Kh8 Probably the best move, but we are mainly interested in the other alternative ( 14… Kxh7 15.Ng5+ Kg8

( 15… Kh8 is a mate in two 16.Qh5+ Kg8 17.Qh7# )

( 15… Kg6 16.Qg4 f5 17.exf6 gxf6 18.Nxe6+ Kf7 and White will win the queen 19.Nxd8+ )

( 15… Kh6 results in a mate in five 16.Qg4 Bxe5 17.dxe5 Nf5 18.Qh3+ Nh4 19.Qxh4+ Kg6 20.Qh7# )

16.Qh5 Be4 17.Nxe4 )

15.Ng5 g6 16.Bxg6 fxg6 17.Qg4 Kg8 18.Qxe6+ Kg7 19.Qh3 Rh8 20.Ne6+ Kg8 21.Nxd8 Rxh3 22.Nxb7 winning a piece

But the game continues for a while.

22… Rh7 23.Nc5 Nbc6 24.Ne4 Rh4 25.Nbd2 Nf5 26.Nf6+ Kg7 27.Nf3 Rxd4 28.Nd5 Rxd5 29.cxd5 Nxe3 30.fxe3 Nxe5 31.Rfb1 Re8 32.e4 Bb6+ 33.Kf1 Nc4 34.Ke2 Na3 35.Rc1 Rxe4+ 36.Kd3 Re3+ 37.Kd2 b3 38.Rxa3 b2 39.Rb1 Rxa3 40.Rxb2 Be3+ 41.Kc2 Kf6 42.Rb3 Ra2+ 43.Kd3 Bc5 44.Rb5 Bd6 45.Rb6 Ke7 46.Nh4 Kd7 47.h3 Ra3+ 48.Kc2 Rg3 49.Ra6 g5 50.Rxd6+ Kc7 51.Rg6 a4 52.Nf3 Rxg2+ 53.Kb1 Rf2 54.Nxg5 Rd2 55.d6+ Rxd6 56.Rxd6 Kxd6 57.h4 Ke5 58.Nf3+ 1-0

A final exercise:
Is the classical bishop sacrifice sound for the following position? The answer will be given in the comments.








White to move
Position after move 16
0 half-moves after last pawn advance or capture

More chess lessons? An index of all chess lessons can be found here.

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Published on February 26th, 2009

chess collage

Tag Galaxy is a 2008 diploma thesis project by Steven Wood that enables you to browse through the galaxy of pictures by entering tags. After entering a tag related tags are shown visualized by other planets in an orbit around the “world” of selected tags.
You’ll have to see it for yourself.

The picture above is the resulting chess+game+king+board world.

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Published on February 11th, 2009

I have upgraded this site to WordPress 2.7.1, the first 2.7 maintenance release. I used the possibility to upgrade automatically and it went very well.