Bishop's Opening: McDonnell Gambit, La Bourdonnais-Denker Gambit

The Bishop's Opening: McDonnell Gambit, La Bourdonnais-Denker Gambit is a chess opening classified under ECO code C23 in the Open Games & French Defense family, beginning with 1.e4 e5 or 1.e4 e6, including the Italian Game, Ruy Lopez, and French Defense. It is reached after 4 moves: 1. e4 e5 2. Bc4 Bc5 3. b4 Bxb4 4. c3. The resulting position leaves black to move.