Game 291 in Philip W. Sergeant’s Morphy’s Games of Chess (1916), printed pages 338–339. Commentary from this edition; named earlier annotators remain credited in the notes. The printed date is September 1857.

1. 18.Qa5 If 18 Kt×P, P—Kt7; 19 B—K3, R—K1; 20 Kt—K5, B—R3; 21 R×B, Q×R; 22 B×B, Q—B8ch, etc. But 18 R—B3 was better (Maroczy).
2. 23.Bg5 Not 23 Kt—B6ch, P×Ktch; 24 K×P, because of 24…Q—B1! Nor does White appear to have any other resource at his command.