[Event "The bakery (blog diagram workshop): Fabulously vicious new problem"] [Site "https://lichess.org/study/l6bOrnM0"] [Result "*"] [Annotator "https://lichess.org/@/Illion"] [Variant "Atomic"] [ECO "?"] [Opening "?"] [FEN "k7/3p4/5p2/2B5/4K3/5P2/2P5/8 w - - 0 1"] [SetUp "1"] [UTCDate "2017.10.20"] [UTCTime "19:55:15"] [Source "https://lichess.org/study/iS3Dp19A/XXiVYZ87"] [Orientation "white"] { White to play and win. It takes some imagination to even realise that white is winning in this position, since black's king appears to have acres of space to roam free. However, white can gradually constrict black to death. The first step is to prevent the space-gaining push ...d7-d5. } 1. Kd5! { The only move that wins. } (1. Kf5? { White has blockaded the f6-pawn on a dark square but cannot win it. White will need to move the king away to threaten a capture but black will then just play ...f5. } 1... d5! $10) (1. Bd6? { While blocking the pawn is the right idea, white leaves the king on a vulnerable square. } 1... Kb7 2. c4 { Else ...Kc6-d5-d4 etc. } 2... Ka6 { Now white needs to prevent ...Ka5-a4 running free, but cannot do so satisfactorily. } 3. Bc7 (3. Be7 d5+! 4. Kf4 dxc4! 5. Bxf6 $10) (3. Kd5 { Too late now. } 3... Ka5 4. Bb4+ Ka4 5. c5 Kb3 $10) 3... d5+! { The d5 fork is the drawing resource. } 4. Kf5 dxc4 $10) (1. Be7? d5+! { ...d5 comes with tempo and draws. } 2. Kd4 f5 $10) 1... Kb7 2. c4! { The correct move order, and again the only move that wins. The bishop waits to see where black's king goes. } (2. Be7? { Committing too early, leaving b6 unguarded. } 2... f5 3. c4 Kb6! { Two escaping threats. } 4. Bd8+ (4. c5+ Ka5) 4... Kc5) (2. Bd4? { Gaining a tempo the other way loses control of d6/d8. } 2... f5 3. c4 Kc7! { Two more escaping threats. } 4. Bb6+ (4. Kd6 Kd8) (4. c5 Kd8) 4... Kd6) (2. Bd6? { This didn't work before and still doesn't work now. } 2... Kc6 3. c4 Kc5) 2... Kc7 { Alternatives transpose or are worse. } (2... Kc6 3. Be7 f5 4. c5) (2... Ka6 3. Bb6 Kb7 4. c5) (2... Kc8 3. Be7 f5 4. c5) 3. Be7! f5 4. c5! { Threatening c6 thus preventing ...Kc6/...Kd6. Now that the whole 3x3 square b7-d7-d5-b5 is mined, white can control black along the edge of the board for zugzwang. Once you're at this point all that's left is to "see" that the black king is trapped and can be forced into zugzwang. } 4... Kb8 { The king has only the 5 squares along the edge to safely move in. } { [%csl Gc8,Gb8,Ga8,Ga7,Ga6] } 5. Bd8 Ka7 6. Bb6+ Kb8 7. Kd6 Kc8 8. Ba5 Kb8 9. Ke7 Ka7 10. Kd8 Kb8 (10... Ka6 11. Bb6 $22 { A key zugzwang motif, with c6 if the king moves. }) 11. Kc8 Ka7 12. Bb6+ Ka8 13. Kb7! { The key move, forcing black into one of two zugzwang patterns. } 13... Kb8 (13... Ka7 14. Kb8! Ka6 (14... Ka8 15. Ba7 $22) 15. Kc8 $22 { Black is forced to allow either c6 or Bxf4. }) 14. Ka8 Kc8 (14... Ka7 15. Kb8 { Transposes to the previous note. }) 15. Kb8 $22 { Black must allow either c6 or Bxf4. } *