KEG: A methodical win by Marco against a weaker opponent. Marco plays an usual opening line to get Rosen out of the books, equalizes within a few moves, misses a chance to get a better game after Rosen's weak 19th move, and then efficiently closes out the game after Rosen's mistake on move 30. Nothing brilliant, just a veteran beating up on a less experienced player.
1. e4 e5
2. Nf3 d6
3. d4 is of course more usual, but the text also gives White good chances.
3...Be7 (recommended by the Tournament Book) or 3...Nc6 are both theoretically better, but the text is playable and avoids any likely prepared lines by Rosen.
4. 0-0 Be7
5. d4 was definitely better, but Rosen seemingly wants to avoid tactical battles with his dangerous opponent.
6. a4, to prevent 6...b5, was better.
Taking advantage of Rosen's failure to play 6. a4
7. Bb3 Nc5
Not best. Marco should have played 7...a5 or 7...Ngf6.
8. d4 NxB
9. axN Qc7
This achieves nothing for White. Rosen should have played 10. Qd3
Driving away the c3 Knight and obtaining a fine pawn wedge on the Queen-side.
Rosenthal in the Tournament Book claims that 11. Ne2 was best, but after 11...Nf6 Black would clearly have the better game.
Fritz says 11...Rb8 is correct, but I like the pawn chain Marco gets with the text.
Since Marco was obviously not going to play 12...bxc3, the text accomplishes nothing and weakens White's Queen-side.
13. Qc2 Nf6
Threatening 15. cxb4 axb4 16. Nxb4! (exploiting the pin on the c-file). But Marco was hardly likely to fall for such a transparent trap. The simple 14. Be3 was therefore best.
Easily parrying Rosen's threat.
15. Nc1 0-0
16. Ne2 Bd7
17. Ng3 Ra7
Rosenthal claims that 18. Ne1 was better, but this makes no sense, since after 18...bxc3 19. bxc3 Rb8 White would have problems dealing with Black's control of the b-file.
This allows 19. Nf5. Marco should have played 18...g6.
Very bad. Rosen should have played 19. Nf5. Now Marco could have obtained King-side chances with 19...h5
Missing his chance to play 19...h5.
20. bxa4 Rxa4
This seemingly automatic move forfeits any advantage Marco had enjoyed. Best was the intermediate move 20...b3.
21. RxR RxR
22. b3 Ra1
This looks stronger than it is.
Rosenthal in the Tournament Book condemns this move, but it looks fine to me. It definitely is better than Rosenthal's proposed 23. Nd3.
Consistent with his last move, Rosen should have played 24. fxe5 or perhaps 24. h3.
Another move that looks much stronger than it is. Best was 24...exf4 or 24...RxR+.
As Rosenthal notes in the Tournament Book, best was simply going for the ending with 25. QxQ+
Once again, 25...exf4 or 25...RxR+ were better.
26. fxe5 dxe5
Rosenthal says that h3 was correct, and that was certainly a reasonable option, but the advance of the d-pawn here is also quite good and presents problems for Marco.
27...Bf8 was better.
Rosen should probably have played 28. h3, but the text is certainly sufficient for equality.
28...Ra2 would probably have led to a draw after 29. Rf2 Qa1+ 30. Rf1 and is thus theoretically best. But Marco was not interested in a draw against this opponent.
After 28...Bb6, Rosen had at least equal chances. But his game fell apart very quickly thereafter as I will show in my next post on this game.