Evans Gambit

The Evans Gambit, 4. b4, gives up the b-pawn to deflect the c5-bishop, so that White gains time for c3 and d4 instead of spending a quiet tempo on 4. c3. After 4...Bxb4, by far the most common reply, 5. c3 hits the bishop again and frees b3 for the queen. The Main Line retreat 5...Ba5 meets 6. d4 with either 6...d6, the Bronstein Defense, or 6...exd4, the Pierce Defense, where the pinned c3-pawn lets White delay recapturing. 5...Be7, the Anderssen Variation, is considered sound, while 5...Bc5, the McDonnell Defense, allows the bishop to be hit once more. The Slow Variation, 6. O-O, avoids the pin. Declining with 4...Bb6 steers play toward queenside expansion and scores well for Black.

William Davies Evans introduced 4. b4 in 1833, and it featured in the 1834 La Bourdonnais–McDonnell matches and in Anderssen's Evergreen Game. Positional play and Lasker's method of returning the pawn to trade queens reduced its appeal; Tartakower's 6. d4 d6 7. Qb3 later revived it. Kasparov used it against Anand in 1995. The engine rates the position as roughly balanced.