Zugzwang

There was an interesting position in a recent game of mine. I'm playing black.

1.e4 c5 2.Nf3 Nc6 3.Bb5 e6 4.O-O Nge7 5.c3 a6 6.Ba4 b5 7.Bc2 Bb7 8.Re1 Rc8 9.a4 Ng6 10.axb5 axb5 11.Na3 b4?!

11...Ra8 is probably better.

12.Nb5 Be7 13.e5 O-O 14.d4 Qb6 15.Bd3 c4!? 16.Bxc4 Nxd4 17.Qxd4 Qxd4 18.cxd4 Rxc4 19.Bg5 Bxf3 20.Bxe7 Nxe7 21.gxf3 Nf5?

21...Rc2

22.Rec1 Rxc1 23.Rxc1 g5 24.Rc4 Nh4

24...Rb8!

25.Rxb4 Nxf3+ 26.Kg2 Nh4+ 27.Kg3 Nf5+ 28.Kg4 f6 29.Rc4 fxe5 30.dxe5 Rb8 31.Rc5 h6 32.b3 Kg7 33.Kh5 Kh7


This is the position, although most of what I'll say about it applies to the position a few moves later, after 35...Kg6 as well.

When I reached this position, I thought it was simply fairly equal. I don't mean a dead draw, since there are still some things to play with: White has a passed pawn, but his pawns are a bit split up; Black has a backwards d-pawn, and a nice knight on f5. However, looking at the position a bit more closely, White has a problem. He has no moves.

Let's go through the possibilities. White's knight can't move without dropping the b-pawn. White's rook can't move without dropping the knight. White does have some pawn moves, but not many, and none that really change the situation. b4 doesn't do much, and actually introduces a tactic once the king goes back to g4; f3 does nothing; h3 does nothing (except block a square the king might need). The king can move back to g4, but that allows the black king into g6, when White still has the same problems, and the added problem of Black pushing the kingside pawns.

Black, on the other hand, has as many waiting moves as needed, just by moving the king between g7 and h7. As a simple variation, if White tries to delay, Black can just wait: 34.f3 Kg7 35.b4 Kh7 36.h3 Kg7 and White is stuck, and probably has to throw away the h-pawn with 37.h4 Nxh4 38.f4 Nf3.

In the game, White retreated the king before using up all the pawn moves, and I was able to press forward for a win.

34.f3 Kg7 35.Kg4 Kg6

This is where the tactic against b4 appears. 36.b4 Nd4! and Black wins the b-pawn after 37.Nxd4 Rxb4, pinning the knight.

36.Kh3 h5 37.Kg2 Ra8 38.Rc7 Ra2+ 39.Kg1 Nh4 40.Rc3 Kh5 41.Re3 Kf4 42.Re4+ Kxf3 43.Re1 Kf4 44.Nd4 Rb2 45.Re2 Rb1+ 46.Kf2 Rh1 47.b4 Rxh2+ 48.Ke1 Rxe2+ 49.Kxe2 Kxe5 50.b5 Nf5 51.Nf3+ Kd6 52.Nxg5 Kc5 53.Kf3 Kxb5 54.Ke4 Kc4 55.Ke5 Kc3 56.Kf6 Ke3 57.Ke5 h4 0-1