KEG: Burn, on the Black side of Petroff's Defense Opening, outplayed Marco and had a won game by about move 20. But his play thereafter was careless and the wily Marco managed to launch a King-side attack that eventually got him a draw.
This was a double loss for Burn, since draws were replayed at Paris 1900 and Marco won the replay.
1. e4 e4
2. Nf3 Nf6
3. Nxe5 d6
4. Nf3 d5
A reasonable alternative to the usual 5. d4, but hardly warranting the lavish praise Rosenthal heaps on it in the Tournament Book.
6. d4 0-0
7. Bd3 Nf6
7...Ng5 is probably a better and easier route to equality.
8. h3 d5
9. Nc3 dxc4
Playing to saddle White with an isolated d-pawn, and raising the perennial question as to whether this is a strength or a weakness. The theme proves to be of no significance in this game, and the isolated d-pawn only falls here on move 41, two moves before the players agree to a draw.
10. Bxc4 Nbd7
10...Nc6 is more promising here, and White now has much the better game. But from here Marco begins to flounder, and within 10 moves his better position becomes a lost one.
It is now yet clear where this Bishop should be posted, and 11. 0-0 or 11. Bb3 were both better than the text.
12. Bb3 Nbd5
Employing the classic method of playing against an isolated d-pawn...blockade it. Here, however, this theme soon becomes irrelevant to the upcoming play.
13. Be5 c6
14. 0-0 Bf5
A useless move, driving Black's Bishop to a good square and misplacing his Knight. 15. Re1 was better.
Another useless move by Marco, who is clearly losing the thread of the game. 16. Rc1 was logical and best.
16...g6 would have effectively neutered White's last move and was best.
I agree with Rosenthal in the Tournament Book that 17. NxN was much better, but best of all may have been the simple 17. Re1.
Better late than never!
In a misguided effort to attack Black's King, Marco ruins his own King-side beyond repair. Rosenthal is certainly correct that 18. g4? loses to Nxg4 (19. hxN BxN), but there was no need for the text. Best was 19. Bb3 or 18. NxN.
Marco has already spoiled his superior position. In just two more moves, he was lost.
Pursuing his reckless plan
19...f6 was best and would have precluded the tactical chance Marco now had at his disposal.
The position was now as follows:
Missing his chance to survivie his prior poor play. With 20. Nf5!, Marco probably had a playable game. With the text, however, his position is probably beyond repair.
If Marco's position wasn't dead lost before, it is now. Come what may, he had to try 20. Qg3
With 21...cxN, Marco would be busted. Burn still has a won position even after the text, but he forces Marco to put the White Queen where it belonged anyway, and frees the f-pawn.
Despite his bad 21st move, Burn should still win this game. But it was now his turn to err badly and ruin his position. How this happened will be covered in my next post on this game.