In chess, Wing Gambit is a generic name given to openings in which White plays an early b4, deflecting an enemy pawn or bishop from c5 so as to regain control of d4, an important central square. (Or in which Black plays ...b5, but Wing Gambits offered by Black are very rare.) The most common Wing Gambit is in the Sicilian Defence (1.e4 c5 2.b4). The most important Wing Gambit is the Evans Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4), treated separately. In the Sicilian Defence The Wing Gambit in the Sicilian Defence runs 1.e4 c5 2.b4 (diagram). After Black takes with 2...cxb4, the usual continuation is 3.a3 bxa3 (3...d5! is more recently considered superior, when White must avoid 4.exd5 Qxd5 5.axb4?? Qe5+ winning the rook, a blunder actually seen in tournament play in Shirazi–Peters, Berkeley 1984; instead 5.Nf3 is better) and now the main line is 4.Nxa3, though 4.Bxa3 and 4.d4 are also seen. It is also possible to decline (or at least delay acceptance of) the gambit with 2...d5. For his pawn, White gets quicker development and a central advantage, but it is not generally considered one of White's better choices against the Sicilian and it is virtually never seen at the professional level. Amongst amateurs it is more common, though still not so popular as other systems. After Black's 2...cxb4, another popular third move alternative for White is 3.d4. GMs George Koltanowski, David Bronstein and World Champion Alexander Alekhine have played this line. White can postpone the gambit one move by playing the Wing Gambit Deferred, playing 2.Nf3 followed by 3.b4. The deferred Wing Gambit is considered to be best when black responds 2...e6. The Portsmouth Gambit runs 2.Nf3 Nc6 3.b4, where Black is disinclined to refuse the gambit due to the positional threat 3.b5, displacing the knight and disrupting Black's smooth development. It is also possible to prepare the gambit by playing 2.a3!? followed by 3.b4. In other openings There is one Wing Gambit in the French Defence; 1.e4 e6 2.Nf3 d5 3.e5 c5 4.b4, although this is quite rare. A related idea is found in the Caro-Kann Defence after 1.e4 c6 2.Ne2 d5 3.e5 c5 4.b4, however Black can immediately achieve an advantage by playing 4...d4! (this move is also strong in the second French line given above). Even rarer is the Wing Gambit in the Bishop's Opening, 1.e4 e5 2.Bc4 Bc5 3.b4, which