About this opening
Petrov's Defense: Classical Attack, Marshall Trap 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 20 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 7. O-O O-O 8. c4 Bg4 9. cxd5 f5 10. Re1 Bxh2+.
It belongs to the Petrov's Defense family.
Within that family this is a level-2 branch (the Classical Attack → Marshall Trap line). The immediate parent line is Petrov's Defense: Classical Attack, transitioned via 10…Bxh2+.
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 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 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.