zydeco: 12....Re8 and 13....c6 are bad mistakes. White could have won immediately with 17.Bc5! Donner saw the move but disregarded it. He writes: "During the game I thought White's position was so good that such a line with sacrifices was not necessary."
Larsen finds a couple of good defensive moves and, by move 22, Donner was already negotiating for a draw. He offered the draw on move 25 and Larsen declined it.
Larsen writes: "I had just declined Donner's offer of a draw, which was very much discussed later, for if and if and if, then I would have won the tournament. But I think I was right to play for a win in this position. A player who knows he must have missed a win often misses the draw as well."
The players disagree about 38....Be4. Larsen thinks it's "very good." Donner suggests 38....Ne4.
Larsen says that 39....Bc2 would have drawn because of 40.Nxa5 Ne6+ 41.Kd5 Bxa4.
39....f5 is a time pressure blunder. White wins a piece after 40.Nd6 because 40....Rc7 runs into 41.Ne8+.