To overcome problems on squares of one color, you can become weak on both.
Alberic O’Kelly White
Ahlback Black
Correspondence 1941
Sicilian Defense E54
1 e4 c5 2 ♘f3 d6 3 d4 cxd4 4 ♘xd4 ♘f6 5 f3
The rare move leaves the c-pawn unblocked so that White can play c2-c4.
5...e5 6 ♘b5
The way to test Black is 6 ♗b5+. Then 6...♘bd7 7 ♘f5 or 6...♗d7 7 ♗xd7+ ♕xd7 8 ♘f5 d5 9 ♗g5! leads to complex play.
6...a6! 7 ♘5c3 ♘bd7?
Black surrenders in the fight for d5. With 7...♗e6! he prepares 8...d5.
8 a4! ♗e7 9 ♘a3 0-0 10 ♘c4 ♘e8?
Black disliked 10...♕c7 because it would add punch to 11 ♘e3 and ♘ed5!. But 10...♘c5 was better.
11 ♘d5
Black’s last move prepared ...♗g5, to get rid of his “bad” bishop. But now he sees that 11...♗g5 12 ♗xg5! ♕xg5 13 ♕d2! ♕xd2+ is a poor endgame because of White’s super knights.
11...f5 12 exf5 ♖xf5 13 ♗d3 ♖f8 14 ♗e3
It looks like Black is worse because of the weak dark squares like b6 and d6. For example, 14......♖b8 15 0-0 ♘ef6 allows 16 ♘xe7+ and 17 ♘xd6 (17...♕xd6? 18 ♗c4+).
But thanks to 11...f5 he also has problems on light squares, even h7, e.g. 15...b6 16 ♗e4 and ♕d3. Both colors do him in:
14...♘df6?? 15 ♗b6! ♕d7 16 ♗f5! resigns.
Pavel Polonsky White
Gennadi Faizrakhmanov Black
Salekhard 2003
1 e4 c5 2 ♘f3 d6 3 d4 cxd4 4 ♘xd4 ♘f6 5 f3 e5 6 ♘b5 a6 7 ♘5c3 ♗e6 8 ♗g5 ♗e7 9 ♗xf6?! ♗xf6 10 ♘d5 ♗xd5 11 ♕xd5 ♘c6 12 ♗c4 0-0 13 ♘c3 ♗g5 14 ♘d1? ♘b4 15 ♕xb7 ♖b8 16 ♕a7 ♘xc2+ 17 ♔f2 ♘xa1 18 ♗d3 ♕a5 White resigns.
Question 98: Why not 14 ♖d1 and ♕xd6 ?