DrGridlock: Bronstein comments on this game in "200 Open Games." The key moment of the game is black's position at move 14. Bronstein writes,
"If you want to suggest 14 ... N-N5 to me, then excellent! If the white queen takes the rook, Black will mate in two with his knight and bishop: 15 QxR? N-B7+ 16 K-K2 B-B5 mate!
However, after the black knight has left QB3 the KB gets the chance to give check and simultaneously free a square for his king's escape: 14 ... N-N5 15 B-QN5+! P-QB3 16 QxR N-B7+ 17 K-B1.
Perhaps Black should have chosen this variation? I do not think so. Instead of 16 ... N-B7+?, it is true that 16 ... QxP! 17 R-KB1 N-B7+! 18 K-K2 B-N5 mate is stronger, but White here tooo need be in no hurry to take the rook. The correct defence would be to check first, 15 B-QN5+, but then hastily to castle: 15 ... P-QB3 16 o-o! since Black's KR in the corner cannot run away from the white queen. I spent quite a bit of time, I remember clearly, looking for some decisive combination in the variation 14 ...N-N5 15 B-QN5+, but just could not find one.
In short, and endgame willy-nilly."