Parallel Games II

In my previous post, Parallel Games, I used a pair of games from Schemingmind.com's Chess960 League - Season One, so it's natural that I follow up with two games from Season Two. The opponents are again both top-10 players on the site and, as luck would have it, I've already had the opportunity to play both of them, finishing 0-2.

The players were assigned start position SP287 NRKNRQBB, which reminded me of the position discussed in NR****Q* & *Q****RN. The difference is that in the current games we have NR****B* instead of NR****Q*, where the Bishop instead of the Queen is positioned to attack the undefended a-Pawn on the diagonal. The top diagram shows the position after 1.f4 f5 2.Bxa7 Bxa2 3.g3 g6 4.Nb3 Bxb1 5.Kxb1 Nb6 6.Bxb8 Kxb8 in the first game; the bottom diagram shows the position after 1.f4 Nb6 2.g3 f5 3.Nb3 g6 4.e4 fxe4 5.Bxe4 e5 in the second. I show one extra move pair in the first game to close the sequence of tactical recaptures.

Both players chose to open 1.f4, a move which attacks the a-Pawn with the Bishop on g1. In the game with NR****Q*, Black had the option of sacrificing the a-Pawn in return for a gain of time by encircling the Queen. In the present position, Black doesn't have this option, because the Bishop on a7 attacks the Rook on b8, threatening to win the exchange. In place of the Pawn sacrifice, Black has the possibility of copying White's tactic with 1...f5. Now the Bishop on g8 attacks the Pawn on a2, threatening to win the Rook on b1.

It's instructive that in one game, Black copied the tactic to win the exchange, while in the other Black declined by blocking the diagonal with ...Nb6. This apparently forced White to do the same. In the first game both players forfeited the castling option by capturing the Bishop with the King. In the second game you might guess that the players would castle O-O-O; in fact, only White castled and, in the other direction, by O-O. Here are the PGN scores of both games, again courtesy of SchemingMind.com.

[Event "Chess960: Chess960 League"]
[Site "SchemingMind.com"]
[Date "2006.05.10"]
[Round "-"]
[White "Tyler"]
[Black "dmichael"]
[Result "1/2-1/2"]
[SetUp "1"]
[FEN "nrknrqbb/pppppppp/8/8/8/8/PPPPPPPP/NRKNRQBB w KQkq - 0 1"]

1.f4 f5 2.Bxa7 Bxa2 3.g3 g6 4.Nb3 Bxb1 5.Kxb1 Nb6 6.Bxb8 Kxb8 7.d4 e6 8.c3 d5 9.e3 Nf7 10.Nf2 Nd6 11.Kc2 Qh6 12.h4 Kc8 13.Nc5 Kd8 14. Bf3 Ke7 15.Qh1 Nbc4 16.b3 Na3+ 17.Kd3 Qf8 18.Ra1 Ra8 19.h5 Bg7 20. hxg6 hxg6 21.g4 c6 22.Kd2 b6 23.Na4 Ndc4+ 24.Ke2 fxg4 25.Nxg4 Qf5 26. Ra2 g5 27.Qc1 Qb1 28.Qxb1 Nxb1 29.Kd3 b5 30.bxc4 Rxa4 31.Rxa4 bxa4 32. Bd1 dxc4+ 33.Kc2 Na3+ 34.Kb2 Nb5 35.Bxa4 gxf4 36.exf4 1/2-1/2

[Event "Chess960: Chess960 League"]
[Site "SchemingMind.com"]
[Date "2006.04.29"]
[Round "-"]
[White "dmichael"]
[Black "Tyler"]
[Result "0-1"]
[SetUp "1"]
[FEN "nrknrqbb/pppppppp/8/8/8/8/PPPPPPPP/NRKNRQBB w KQkq - 0 1"]

1.f4 Nb6 2.g3 f5 3.Nb3 g6 4.e4 fxe4 5.Bxe4 e5 6.Bc5 d6 7.Bxb6 axb6 8.Qh3+ Ne6 9.fxe5 Bg7 10.Nd4 c6 11.Nxe6 Rxe6 12.exd6 Qxd6 13.Bd3 Qd7 14.Ne3 b5 15.a3 Kc7 16.Qg4 Qe7 17.Qf4+ Be5 18.Qg4 Rd8 19.O-O h5 20. Qf3 h4 21.g4 Bd4 22.Qf4+ Kc8 23.Rfe1 Bc5 24.Qf3 Qg5 25.b4 Rf8 26.Qh3 Bb6 27.Bf1 Rd8 28.Kh1 Rxd2 0-1

Since the games ended with different results, it's natural to look for the reason in the early moves. Is it a coincidence that the draw resulted from the game where two pieces -- a Rook and a Bishop -- disappeared from the board in the first few moves?