About this opening
Petrov's Defense: Classical Attack, Marshall Variation is an opening in the Encyclopedia of Chess Openings,
classified under code C42. ECO group C (C00–C99)
covers open games (1.e4 e5) and the French Defence, including the Ruy Lopez, Italian, Scotch and King's Gambit. This particular variation is reached
after 12 half-moves from the
starting position, with the move sequence 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Bd6.
It belongs to the Petrov's Defense family.
Within that family this is a level-2 branch (the Classical Attack → Marshall Variation line). The immediate parent line is Petrov's Defense: Classical Attack, transitioned via 6…Bd6.
The opening sequence in prose form: 1.e4 e5, 2.Nf3 Nf6, 3.Nxe5 d6, 4.Nf3 Nxe4, 5.d4 d5, 6.Bd3 Bd6. From this position exactly one named continuation is recorded in the encyclopaedia.
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. The list of recorded continuations sits directly below the board. 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 C42 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.