White chose to exchange a knight against two pawns and an exposed king. While this gambit is considered as dubious, it can lead to a quick victory if black doesn't know how to play it. Few of these games end in a draw.
For explanation of theory tables see theory table and for notation see algebraic notation.
1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nxf7
When contributing to this Wikibook, please follow the Conventions for organization.
Wikipedia has related information at Petrov Defence