Passed pawns must be pushed.
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[Event "rated untimed match"]
[Site "USSR"]
[Date "1961.??.??"]
[Round "?"]
[White "Bubnov"]
[Black "Terpugov"]
[Result "0-1"]
[Annotator "David Hayes"]
[BlackElo "0"]
[FEN "2k5/1p2b3/2p1p3/3pP1p1/nP1P2P1/NKP5/3B4/q3Q3 b - - 0 1"]
[SetUp "1"]
[TimeControl "0"]
[WhiteElo "0"]
1... Qb2+ 2. Kxa4 b5+ ( { Black has the pleasant option to press his attack
in several ways. Like this: } 2... Qa2 3. Qc1 b5+ 4. Ka5 Kb7 5. Bxg5 Bxg5 6. Qxg5 Qxa3# ) 3. Ka5 ( { White can try to delay matters: } 3. Nxb5 cxb5+ 4. Kxb5 Kb7 5. Bc1 Qa2 6. Ba3 Qxa3 7. Qa1 Qxa1 8. c4 Qa6# ) 3... Bd8+ 4. Ka6 Qxa3# 0-1