About this opening
Alekhine Defense: Four Pawns Attack, Korchnoi Variation is an opening in the Encyclopedia of Chess Openings,
classified under code B03. ECO group B (B00–B99)
covers semi-open games (1.e4 with Black playing anything other than 1…e5), with the Sicilian, French, Caro-Kann and Pirc/Modern at its heart. This particular variation is reached
after 20 half-moves from the
starting position, with the move sequence 1. e4 Nf6 2. e5 Nd5 3. d4 d6 4. c4 Nb6 5. f4 dxe5 6. fxe5 Bf5 7. Nc3 e6 8. Nf3 Be7 9. Be2 O-O 10. O-O f6.
It belongs to the Alekhine Defense family.
Within that family this is a level-2 branch (the Four Pawns Attack → Korchnoi Variation line). The immediate parent line is Alekhine Defense: Four Pawns Attack, transitioned via 10…f6.
The opening sequence in prose form: 1.e4 Nf6, 2.e5 Nd5, 3.d4 d6, 4.c4 Nb6, 5.f4 dxe5, 6.fxe5 Bf5. From this position the encyclopaedia records no further canonical continuations — practical play branches into unnamed transpositions or returns to the parent line for alternative ideas.
Use the interactive board above to walk through the moves position-by-position. Click any move in the navigation to step backwards, or use the keyboard arrow keys. For statistical data — how often master-level players have reached this position, White's win-rate, draw frequency, Black's score — see the panel in the right column.
Caissly's coverage of B03 extends through every named sub-variation in this line and across all four locales (English, Spanish, Portuguese, Russian). Where editorial commentary exists for a specific variation it appears as the page body; otherwise the page presents the structural data, board, and statistics as shown here.