[Event "?"] [Site "?"] [Round "0"] [White "Botvinnik"] [Black "Flohr"] [Result "1/2-1/2"] [FEN "5k2/2q2npp/1ppp1p2/5P2/2P2P2/1P2Q1P1/6BP/6K1 w - - 0 1"] [ECO "A00"] [Opening "Polish: 1...d5"] {Another borderline case with Knight against Bishop The game was adjourned in this position, and it was thought that 1. Bf3 might win.} 1. b4 d5 $3 { A pretty sacrifice which kills two birds with one stone: the White Bishop becomes bad, as it must now keep an eye on the d-pawn, while the Black Knight becomes veryactive} 2. cxd5 c5 3. bxc5 bxc5 4. Bf1 Nd6 {The Knight an ideal piece for stopping passed pawn. The d6 square is the so-called "blockaded square" in this position. It is only in recent times that the importance of the blockade has been fully realized} 5. Qa3 Kf7 6. Bd3 c4 7. Bc2 c3 (7... Qb6+ 8. Kf1 Ke7) 8. Qb4 Nc4 9. Qxc3 Qc5+ 10. Kh1 Qxd5+ $11 1/2-1/2