Thursday, January 22, 2015

Add this Chess960 start to the list of difficult SP's black must face?

Since Chess960 was invented, SP408 has never been played in real world competition. It is a serious intelligence test for black after white plays the move 1.d4.

SP408 Black to play: How to respond to 1.d4?

The problem is that the d5 square cannot be comfortably supported in such a way that assist black's development. For example, ...d5/e6 blocks a development square for a knight. If black plays ...d5/c6, yes that frees the dark bishop, but white has natural developing moves that undermine the d5 square:

1. d4...d5
2. Nfe3 {attacking d5} c6
3. c4! {threatening to draw a pawn onto the weak d5 square}

The big question is, what does black do about supporting the weak d5 square in a way that assists development?

Well since no human has played this SP in competition, I turned to the CCRL database of computer engines instead. The stats are not promising for black with a 62% - 38% win rate for white which is pretty high. A lot of engines, in particular Houdini 4, will try to play this line:

1. d4...c4
2. d5!? {preventing black's knights from developing toward the center} c4?!

However, I found one game played by Stockfish 5 that I think is a very memorable win for black, spoiled only by Critter's bad opening idea to push the a-pawn aggessively. Stockfish bypasses the d5 problem altogether by appearing to play ultra conservatively minimising any weaknesses, then only later beginning to apply pressure.

This is a stunning opening by Stockfish, as if it were intelligent. Critter is made to look foolish I think!

SP408 Critter plays a kind of Queen's Gambit Declined Slav?
Ok here is one possible answer to the problem of 1.d4 in SP408!
1.d4...d5
2.Nfe3...c6
3.c4...Nde6! {So black attacks the very same weak square that white attacks}
4.cxd5...Nxd4

Nice idea, brilliant! What is this in theory? A counter gambit on a weak square? Ideas like this are never seen in standard chess...