[Event "Variantim"] [Site "?"] [Date "2023.??.??"] [Round "?"] [White "Rusz, Arpad"] [Black "(Study 195)"] [Result "1/2-1/2"] [Annotator "Honourable Mention"] [SetUp "1"] [FEN "k7/3p4/P3b3/8/1N2K2p/8/8/8 w - - 0 1"] [PlyCount "31"] [GameId "2092318380741890"] {[%evp 0,31,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,-192,0,0,0,0,0,0,0,0]} 1. Kf3 Ka7 2. Kg2 Kb6 3. Kh1 $3 {Mutual zugwang! As we will see, from now on, the white king's moves are guided by the theory of corresponding squares. For all available squares for the bishop on the c8-h3 diagonal (e6, f5, g4, and h3), there is a corresponding square in the lower right corner of the board.} (3. Kh2 $2 Bf5 $1 {zz} 4. Kg2 Kb5 $1 5. a7 Be4+ 6. Kh3 Kxb4 $19) (3. Kg1 $2 Bh3 $1 {zz} 4. Kh1 d6 $1 {zz} 5. Kg1 Bf5 $1 {zz} 6. Kh2 Bc8 $1 {zz} 7. Kg2 {The king should stay close to the h-pawn and be ready to attack it if the bishop captures the white pawn.} Kb5 8. a7 Bb7+ 9. Kh3 Kxb4 $19) (3. Kf3 $2 Bh3 4. Kf4 Bg2 5. Kg4 h3 6. Kg3 d6 $1 (6... Kb5 $2 7. Nd3 Kxa6 8. Nc5+ $19) 7. Kh2 Kb5 $19) 3... Bh3 4. Kg1 $3 {Mutual zugwang! As we will see, from now on, the white king's moves are guided by the theory of corresponding squares. For all available squares for the bishop on the c8-h3 diagonal (e6, f5, g4, and h3), there is a corresponding square in the lower right corner of the board.} Bg4 5. Kg2 $1 {zz} (5. Kh1 $2 Kb5 6. a7 Bf3+ 7. Kh2 Kxb4 $19) 5... Bf5 6. Kh2 $1 {zz} Be6 7. Kh1 d6 {Moving this pawn seems to be a very good idea as we can increase the number of squares available for the bishop on the diagonal from 4 to 6 squares. There is no way the white king can cope with that!} 8. Kg2 $1 {zz} (8. Kg1 $2 Bf5 $1 {zz} 9. Kh2 Bc8 $1 $19 {zz}) 8... Bf5 9. Kg1 $1 {zz} Bh3 10. Kh1 $1 {zz} Bc8 11. Kh2 $1 {zz} Be6 (11... Bxa6 12. Kh3 $11) 12. Kg2 {So far the white king managed to counter all bishop positions but we didn't use two of them yet: one new (d7) and one old (g4).} Bd7 $5 {After this waiting move, all king moves should lose... The salvation comes from the knight. When black moved the pawn to d6, that had a surprising side effect: the pawn became more vulnerable to knight attacks! Although the knight needs 3 moves to attack it, we will see that it can gain the necessary tempos.} 13. Nd5+ $1 {One.} (13. Kh2 $2 Bc8 $1 $19 {zz}) (13. Kg1 $2 Bf5 $1 $19 {zz}) (13. Kh1 $2 Bh3 $1 $19 {zz}) 13... Kxa6 14. Nf6 $1 {Two!} Bc8 15. Ne8 $1 {Here we are!} d5 16. Nc7+ $11 {So the d7 square was actually forbidden for the bishop. From f6, the knight attacks the g4 square too, so a similar gain of tempo would have been possible if the bishop had moved there. That means we were again left with only 4 available squares for the bishop on that diagonal (c8, e6, f5, and h3), and the previous play was again fully guided by (a completely different set of) corresponding squares between the Bishop and the King!} 1/2-1/2