zydeco: Najdorf writes that he was worried about some opening surprise and played the opening more cautiously than usual. 8.Be2 was "an excess of prudence." After 8....c5, Najdorf felt that black was already very close to equality. He traded pawns on move 10 to keep a minimal advantage.
Donner offered a draw on move 17. Najdorf refused. Donner writes, "This annoyed me very much, and that is probably the reason for my horrible play later on."
Donner doesn't perceive white's plan from move 18 to 22. White wants to trade dark-squared bishops and maneuver the knight to c5. Donner obliges by provoking 19.e4, which plays straight into white's hands.
Donner missed 28.e5!
28....Nc7 was a better try.
Donner missed that he couldn't restore material equality with 31....Qxe5 because of 32.Qc6 and the rook is trapped on a8.
Donner concludes: "This horrible game spoiled the fun of the tournament for me." Donner had a 50% score through 11 rounds, and then, starting with this debacle, managed only one a half-point over the last seven rounds.