Evans Gambit, Main Line

With 5...Ba5 Black keeps the gambit pawn and leaves the bishop on the a5–e1 diagonal. Once White plays d4, the c3-pawn is pinned to the king, which makes the central exchange awkward to resolve and gives Black targets on the queenside. The retreat is regarded as Black's most ambitious attempt to refute 4. b4, though it carries more risk than the quieter 5...Be7. White is a pawn down, with an isolated a-pawn and a half-open b-file in compensation for lost time.

6. d4 is by far the most frequent reply. It strikes at the center at once and meets four main responses: 6...exd4, 6...d6, 6...Nf6 and 6...b5. 6. O-O, the Slow Variation, unpins the c3-pawn before White commits in the center, but it scores noticeably worse for White. 6. Qb3 lines up the queen and the c4-bishop against f7. The engine considers the position roughly balanced, with a slight lean toward Black, and practical results are close to even.