Chessical: This game won the second brilliancy prize in the tournament.A slightly later game Bernstein - Burn St Petersburg, 1909 continued 9...c6 10.d5 c5 11.f4 exf4 12.gxf4 Nh5 13.Kh2 f5! 14.Bf3 Ndf6 15.e5 dxe5 16.fxe5 Rxe5 and Black went onto win. Burn has a reputation for being a dry positional player, but he contributed to early twentienth century Indian theory,e.g. using Nc6 in the King's Indian.
Having played 10.Qxd4 the c4 pawn is weak, but to protect it by say 11.Nf4 is passive, so White sacs it for a great deal of space. Chigorin was a powerful gambit player with a taste of the initiative, long term defence would have been less to his taste. Alternatively this line was an inspired finger slip by Cohn! 11.Nf4 g6 12.b3 Bg7 13.Qe3 in unimpressive
15... Qa5 He does not like the threat of e5. Thus after15...g6 16.e5 Nd7 17.Ne4 Qa5 18.N2c3 Rd8 19.Nxd6 and White dominates the board.
16...Rb8 may have been a better porcatical chance: 17.e5 dxe5 18.Bxc6 bxc6 19.fxe5 Rxe5 20.Na4 Rd5 21.Bxf6 gxf6 22.Qxf6 Qc7 with a messy position.
21...Qxa2? is a blunder. He cannot ignore the theat to c7 and take the a pawn. 22.Nc7 d5 23.Nxe8 22.h4 Nb6 23.f5 White gets more space
23...Nd7 which is Marco's defensive suggestion does not seem to improve matters. 24.Rc1 Nc5 25.f6 g6 26.e5 Ne6 27.Ne7+ Bxe7 28.fxe7 Rxe7 29.exd6 Rd7 30.Rd3 f5 31.gxf6 Kf7 32.Qe3 with a winning position.
27...Re7!? is an interesting alternative for Black. One rough line is: 28.Rd4 Bxg2 29.Kxg2 Qc8 30.Re4 Qc6 31.Qf5 Qc5 32.Bf6 gxf6 33.gxf6 Qxf5 34.Rxf5 Rc7 35.Rg5+ Kh8 36.Kf3 Rac8. White has sacrificed a bishop but I cannot see a clear winning plan. Anyone got an improvement?
Taking the bishop is, however, too dangerous. White then mates using both bishops trained on the Black King and pressure down the f file. One example being 28.Bxd5 Kh8 29.Bd4 Be7 30.Bxg7+ Kxg7 31.Qf7+ Kh8 32.Be4 Qb6+ 33.Kh1 Bf8 34.Qxh7 mate
"A boldly contested game" - Tartakower
Kibitzing
