Morphy Defense, Norwegian Variation

The Norwegian Variation, 5...Na5, also called the Taimanov Variation, hunts the Spanish bishop and spends time to win the bishop pair. The bishop has no escape, so White usually develops with 6. O-O, which turns Nxe5 into a real threat. The popular grab 6. Nxe5 allows 6...Nxb3 7. axb3 Qg5, regaining the pawn, while 6. Bxf7+ is the Nightingale Gambit. Named for Svein Johannessen, it remains a sideline in which White keeps a slight edge.