About this opening
London System: Poisoned Pawn Variation is an opening in the Encyclopedia of Chess Openings,
classified under code D02. ECO group D (D00–D99)
covers closed games and semi-closed games beginning 1.d4 d5, covering the Queen's Gambit, Slav, Grünfeld and related queen-pawn structures. This particular variation is reached
after 9 half-moves from the
starting position, with the move sequence 1. d4 Nf6 2. Nf3 d5 3. Bf4 c5 4. e3 Qb6 5. Nc3.
It belongs to the London System family. Within that family this is a sub-variation (the Poisoned Pawn Variation line).
The opening sequence in prose form: 1.d4 Nf6, 2.Nf3 d5, 3.Bf4 c5, 4.e3 Qb6, 5.Nc3. 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 D02 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.