Game 242 in Philip W. Sergeant’s Morphy’s Games of Chess (1916), printed pages 298. Commentary from this edition; named earlier annotators remain credited in the notes.

1. 12.Nd2 To this point the play has followed Games LXXIV and LXXXIV. Here, however, the first game continued 12 B—K3; the second 12 Kt—QB3. See the notes on LXXIV.
2. 12…f5 In this game, as in LXXXIV against the same opponent, Morphy finds time to make the advance of the KBP for which his 11th move prepared.
3. 15…f4 And this is decisive.