31 May 2008

Boden's Mate

White to move. Can White steal the free pawn on b7?

29 May 2008

Camp Preparation

In the 1903 Russian Championship, Ossip Bernstein had Black and move against Stefan Izbinsky. The game ended in a draw because Bernstein missed the win. What is the winning idea?

20 May 2008

Pawn Race

White to move. Who wins the race?

15 May 2008

Chess World Puzzles

This morning I tried a few of the rated puzzles on ChessWorld, which has recently added this feature. One of the puzzles demanded that it be shared.

White to move.

ChessWorld is a correspondence site, or site for turn-based chess, as some call it. I've found no similar site with as many features, with such high quality play, and run by an accomplished and visible administrator.

Tryfon Gavriel (aka Kingcrusher) of the Barnet Chess Club is the webmaster.

13 May 2008

Bookmark Purge

It's time to get rid of some bookmarks that I no longer use, but perhaps someone else wants them.

The engine at Accoona keeps learning, or so they say, but I dislike the inability to save a game if I play a good one against it. The board is also too small.

I enjoy turn-based chess (a form of correspondence). Not all sites offering this sort of play are equal, however. ChessHere.com is good, but not top class.

Chess Mail is another turn-based site that lacks the quality to put it in the same league as ChessWorld.

has morphed more often than most insects, and the quality has improved ever so slightly. It has never been a bad place to play, but it has never been worth the cost either, except when they offered free accounts to USCF members. Internet Chess Club acquired World Chess Network and Chess Live, merged them into World Chess Live, but keeps them separate from ICC. As they share the same software, it becomes difficult to maintain accounts at both ICC and World Chess Live. In any case, ICC is no longer the leader it was a few years ago. Playchess has taken the lead while the ICC administrators have focused on corporate growth more than chess site improvement.

12 May 2008

Breakthrough and Opposition

While probing the depths of the ChessBase database indexes, I came across this tragicomedy from the 2003 8th All-Africa Games. Mark Dvoretsky employs the term tragicomedy for violations of basic endgame principles by strong players—missing technical wins or draws. In this case, Angola team member Ediberto Domingos missed a win against Kamel Sebih of Algeria.

From its beginning as a Dutch Defense (ECO A85), the game was a positional struggle that came down to a materially equal endgame. Then, Domingos, as White, gave up a pawn for a more active king. A few moves later Sebih gave the pawn back and brought his king into the struggle.

With 46…b4, Black gave up a piece to create a powerful passed pawn.

The game continued 47.Bb6+ Ka4 48.Bxc7 b3 49.Be5 Ka3. We reach the position that caught my interest this morning.

It appears to me that the white bishop must immolate itself for the passed pawn, but that White then has a won king and pawn endgame. As is my practice, I opened the position in Hiarcs and tested my ideas against the Silicon Beast. I was able to win several ways.

50.h4! +-

50.Kd5! +-

50.g4!! +-

I favor the dramatic 50.g4 because it offers the most rapid demonstration of the superior placement of White’s king. The game against Hiarcs continued 50…Ka2 51.gxf5 gxf5 52.Kd5 Kb1 53.Bd4 Kc2 54.Ke5 and the result should be clear (see diagram to right).

I did not like Ediberto Domingos’ fiftieth move: 50.Kd6, although as it turns out, that move also wins. The game continued 50…b2 51.Bxb2 Kxb2 reaching the next diagram position (below).

Here Domingos blundered (the tragicomedy) with 52.Ke7?? This move suggests that White’s idea behind 50.Kd6 was to head towards the h-pawn. However, e5 is just as close to the h-pawn as e7. Moreover, this strategy loses tactically—it becomes a pawn race that favors Black. White should aim for a breakthrough in the center.

White still could have won with 52.Ke5 or 52.g4, and perhaps even with 52.Kd5.

11 May 2008

Pawn Stoppers

Assess White's chances. Win, loss, draw?