notyetagm: Black To Play: 36 ... ?
 click for larger viewWhite has just blundered by meeting the check from the Black d5-queen against the White g2-king by <BLOCKING> with 36 ♕g4-f3??. Why is this a blunder? When White <BLOCKED> the check with his queen, his queen became both <PINNED> and <LOOSE>. Now the White g2-king is the only White piece that meets the threat of ... ♕x♕ by <DEFENDING> her. Note that if the White g3-pawn and Black g6-knight were not on the g-file, then Black could <REMOVE THE GUARD> of the <LOOSE> White f3-queen by <DRIVING OFF> the White g2-king with ... ♖g8+. <So the White g3-pawn must stay on the g-file to <BLOCK> the g-file to prevent this threat, since Black might move his g6-knight out of the way with tempo.> Well, if the White g3-pawn must <BLOCK> the g-file, then it cannot also <DEFEND> the h4-square. Or, as I like to say, <BLOCKING A LINE IS A FULL-TIME JOB>. So Black plays 36 ... ♘h4+!, <FORKING> the White king and queen. If White responds to the knight fork with 37 gxh4, then the g-file is opened and 37 ... ♖g8+ <DRIVES OFF> the White king from <DEFENDING> the White queen. Position after 36 ... ♘h4+! 37 gxh4 ♖g8+:
 click for larger view35 ... ♕xd5+ 36 ♕f3?? ♘f4+! 0-1 (37 gxh4 ♖g8+ <remove the guard> and 38 ... ♕x♕) |