Daniele Gatti & Mario Micaloni (Italy)
Black Knight must be captured or comes 1. … Se4 with double attack. Example: 1. f7? Se4 2. Rd3+ g3 3. Be1 Bc5! Promotion in f8 is stopped and mate threats are unblockable [–+]
Try: 1.Bxc3? Direct capture is ineffective: 1…g3! 2.Rd2 Bf2! 3.Rd3 e4! Overloading 4.Rxg3+ Kxg3 5.Bb4 Bd4! 6.f7 Bg7! 7.f5 Kg4 8.f6 Bh6! 9.Kxh2 Kf5 10.Kg3 Kxf6! 11.f8Q+ Bxf8 12.Bxf8 Ke5–+ Promotion in f8 is stopped and mate threats are unblockable
1…g3 2.Rxc3 Bd4 3.Ra3 h4 4.fxe5 Bb2 5.Rf3
5.Rd3? a3! 6.Bc1 Bxc1 7.f7 Be3! 8.Rxe3 a2 9.Ra3 a1Q+ 10.Rxa1 g2#
5…a3 6.Bc1! Bxc1 7.f7 Bh6 8.Rxa3 and even if white pawns cannot reach 8th rank, no progress is possible for Black (= positional draw).