Ex cathedra

[Event "Match per Campionato del Mondo"]
[Site "New York"]
[Date "1886.03.24"]
[Round "19"]
[White "Zukertort, Johannes Hermann"]
[Black "Steinitz, Wilhelm"]
[ECO "D53"]
[Result "0-1"]
[Annotator "Fischer, Robert James"]
[PlyCount "58"]

1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 Be7 5. Nf3 O-O 6. c5 {White plays a mistake already; he should just play 6. e3, naturally.} 6... b6 7. b4 bxc5 8. dxc5 a5 9. a3 {Now he plays this fantastic move; it's the winning move.} 9... d4 {He can't take with the knight, because of axb4.} 10. Bxf6 gxf6 11. Na4 e5 {This kingside weakness is nothing; the center is easily winning.} 12. b5 Be6 13. g3 c6 14. bxc6 Nxc6 15. Bg2 Rb8 {Threatening Bb3.} 16. Qc1 d3 17. e3 e4 18. Nd2 f5 19. O-O Re8 {A very modern move; a quiet positional move. The rook is doing nothing now, but later...} 20. f3 {To break up the center, it's his only chance.} 20... Nd4 21. exd4 Qxd4+ 22. Kh1 e3 23. Nc3 Bf6 24. Ndb1 d2 25. Qc2 Bb3 26. Qxf5 d1=Q 27. Nxd1 Bxd1 28. Nc3 e2 29. Raxd1 Qxc3 0-1