Evans Gambit, McDonnell Defense

The McDonnell Defense answers 5. c3 by returning the bishop to c5 instead of choosing the more common 5...Ba5 or 5...Be7. The retreat does not stop White's central advance. 6. d4, chosen in the vast majority of games, attacks the bishop once more and strikes at e5, gaining a further tempo. The alternatives 6. O-O and 6. Qb3 are much rarer, and the queen sortie scores noticeably worse for White.

The Main Line runs 6. d4 exd4 7. O-O d6 8. cxd4 Bb6. White castles before recapturing, then takes back on d4 to set up pawns on e4 and d4, with open lines and quick development as compensation for the pawn. Black keeps the extra material and a solid d6-e5 type setup, and the bishop on b6 bears down on d4. The play is sharp and largely about whether Black can complete development before White's central pressure and attacking chances take effect. The engine considers the position roughly balanced, but White scores well in practice, and the line is mostly seen at club level.