Chess Opening Theory/1. e4/1...e6/2. d4/2...d5/3. Nc3/3...Bb4

Winawer variation C15-C19 Paulsen variation 3...Bb4 · Winawer variation Black immediately seizes the occasion to get rid of the white knight. An exchange is almost inevitable. By pinning the knight, the e-pawn is left unprotected. White can put his pawn out of danger with /4. e5/, which is considered to be the main line of the Winawer. It should be noted that the dark-squared bishop is Black's "good bishop," as the light-squared bishop is stuck behind the pawn chain. The exchange however does give Black some compensation after the usual 4. e5 c5 5. a3 Bxc3 6. bxc3 as the closed position is quite solid for Black and their superior queenside is more agile than White's jammed centre. However after the usual and flexible 6...Ne7 White can choose between the tactical and very complex poisoned pawn variation (7. Qg4) or the strategic and complex lines following either a4 or Nf3. Play can be very difficult with lots of good chances for both players. Apart from pushing the pawn forward, White has many alternatives for either protecting or gambiting the pawn. /4. exd5/ turns the position into an exchange variation with Nc3 and ...Bb4 interposed. The addition of these two moves does create a more imbalanced position, making this variation somewhat less prone to drawn positions, unlike the original exchange variation. /4. Ne2/ is the Alekhine-Maróczy gambit. White gambits the e4-pawn for a lead in development, intending to force Bxc3 with a3 and recapturing with the knight. White has an easier time developing their pieces while Black tries to fend off their attack. /4. Bd3/ is popular at the amateur level, protecting the pawn with the bishop. This move isn't played much at the grandmaster level since Black enjoys fairly simple equality after 4...dxe4 5. Bxe4 Nf6 6. Bf3 O-O with e5 and/or c5 incoming. /4. a3/ forces Black to exchange the bishop and intends to harass the kingside, which has now been weakened due to the missing bishop, with Qg4. /4. Bd2/ is the Fingerslip variation, which leads to dangerous positions where White gives up a central pawn for development and piece activity. Theory table all Main line 4. e5 c5 5. a3 Bxc3+ + Bogoljubow variation 4. ... ... 5. Bd2 Ne7 Exchange variation 4. exd5 exd5 5. Bd3 Nc6 Winckelmann-Reimer gambit 4. a3 Bxc3+ 5. bxc3 dxe4 6. f3 Alekhine-Maróczy gambit 4. Ne2 dxe4 5. a3 Bxc3+ 4. Bd3 exd4 5. Bxd4 Nf6 Fingerslip variation 4. Bd2 exd4 5. Qg4 Nf6 References French Defence