[Event "Nottingham"] [Site "Nottingham"] [Date "1936.??.??"] [Round "?"] [White "Botvinnik, Mikhail"] [Black "Tartakower, Saviely"] [Result "1-0"] [ECO "A55"] [Annotator "peter"] [SetUp "1"] [FEN "r3r3/pp1bbpk1/2q2nnp/2PNp3/2N1P3/4B2P/PP4B1/2RQ1RK1 w - - 0 20"] [PlyCount "21"] [EventDate "1936.08.10"] [EventType "tourn"] [EventRounds "14"] [EventCountry "ENG"] [SourceTitle "HCL"] [Source "ChessBase"] [SourceDate "1999.07.01"] [SourceVersion "2"] [SourceVersionDate "1999.07.01"] [SourceQuality "1"] {[#]} 20. Nd6 $1 {At first sight a threat to win the exchange} Be6 (20... Rf8 { if Black tries to save the rook worse befalls him} 21. Nxe7 Nxe7 22. Rxf6 Kxf6 23. Qh5 Ng8 24. Bxh6 Ke7 (24... Nxh6 25. Qxh6+ Ke7 26. Qg5+ f6 27. Qg7+ Kd8 28. Qxf8+) 25. Qxe5+ Be6 26. Nf5+ {is decisive e.g.} Ke8 27. Bxf8 Kxf8 28. Qg7+ Ke8 29. Qxg8+) (20... Bxd6 21. Rxf6 {loses the bishop on d6 because of the discovered attack on the c-file, e.g.} (21. cxd6 {also wins but is far messier after} Nxd5) 21... Re6 22. cxd6 $18) 21. Nxe7 {It turns out White is after more than the exchange!} (21. Nxe8+ {was good enough but would have allowed Black to struggle on an exchange down}) 21... Nxe7 (21... Rxe7 22. Nf5+ Bxf5 ( 22... Kh7 23. Nxe7) 23. exf5 {with a discovered attack on the queen}) 22. Rxf6 $1 Kxf6 23. Qh5 Ng6 24. Nf5 {cutting off the Black king's escape} Rg8 (24... Bxf5 25. exf5 Qa4 26. fxg6 fxg6 27. Rf1+ $18 {with mate to follow quickly}) 25. Qxh6 {threatening Bg5 mate} Bxa2 26. Rd1 {intending Rd6+} Rad8 27. Qg5+ Ke6 28. Rxd8 f6 29. Rxg8 Nf4 (29... fxg5 30. Rxg6+ Kd7 31. Rxc6) 30. Qg7 {All very nicely calculated!} 1-0