Chess Opening Theory/1. d4/1...Nf6/2. c4/2...e5/3. dxe5

Budapest defence A51-A52 Budapest defence 3. dxe5 White accepts the free pawn. This comes with tempo on Black's knight, so Black's must decide where to move it. 3...Ng4 is the main line Budapest. This saves the knight and prepares to recapture the pawn. The next few moves revolve around the defence of or attack on the e5 pawn. After 4. Nf3, the Adler variation, White usually can't bring enough defenders so allows Black to take the pawn back and prioritises their piece development instead. Alekhine advocated 4. e4, giving the pawn back immediately without a fight. In the main line, 4. Bf4, the Rubinstein variation, White does have the choice of hanging onto the pawn, but only if they decide it is worth having doubled c-pawns themselves. The alternative is 3...Ne4, the Fajarowicz variation. Black sees no urgency in recovering the pawn and would rather prioritise activity. Theory table 1.d4 Nf6 2.c4 e5 3.dxe5 3 4 5 6 7 Fajarowicz gambit ...Ne4 Nf3Nc6 a3d6 Qc2Bf5 Nc3Nxf2 += Adler variation ...Ng4 Nf3Bc5 e3Nc6 Be2O-O O-ORe8 += Rubinstein variation ...... Bf4Nc6 Nf3Bb4+ Nbd2Qe7 e3Ngxe5 += ...... ...... ...... Nc3Bxc3+ bxc3Qe7 += ...... ...g5 Bg3Bg7 Nf3Nc6 Nc3Ngxe5 += Alekhine variation ...... e4Nxe5 f4Nec6 a3a5 Be3Na6 += References See also Budapest Gambit