Chess Opening Theory/1. b4/1...e5/2. Bb2/2...Bxb4

=Polish Opening, Main Line=

2...Bxb4
Black takes the undefended pawn which will most likely result in White recapturing with 3. Bxe5. Not only has Black now ceded White a central pawn majority for the b-pawn, but Black also has to worry about white's threat on g7. Also, a sharper but very risky option for White is 3. f4?!. At this point, Black can safely gain some form of advantage with 3...d6 4. fxe5 dxe5 5. Bxe5, due to white's weakened kingside and missing f-pawn. Black has, on the other hand, traded two central pawns for two flank pawns. Black can also accept the gambit with 3...exf4?!, leading to wild play and an unclear position after 4. Bxg7 Qh4+! 5. g3 fxg3 6. Bg2! gxh2+ 7. Kf1 hxg1=Q+ 8. Kxg1 Qg3 9. Bxh8, where White has a rook and a pawn for a knight and three pawns. The board is wide open and both sides have possibilities, though computers evaluate the position as objectively better for White. Nevertheless, computer evaluation has suggested that 3...Nh6! gives Black a large, if not winning advantage.

Theory table
'''1. b4 e5 2. Bb2 Bxb4'''