Opening Leak Lab

Queen's Gambit Declined: Three Knights Variation

D37 1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Nf3 Be7 5. e3 O-O

Black scores 44.9% here across 839 club games — but the 10.7% who answer c5 score 41.7%, 3 points worse.

What Black actually plays here

Across 839 games from a Lichess-derived book of club play, Black scores 44.9% in this position. These are the replies people choose, and how each one works out.

ReplyGamesShare Black scoresVerdict
Be7 216 25.7% 48.6% holds up
Bb4 193 23.0% 42.0% holds up
c6 136 16.2% 51.5% holds up
c5 90 10.7% 41.7% below the line
Nbd7 59 7.0% 50.8% holds up
b6 49 5.8% 41.8% below the line
a6 30 3.6% 43.3% holds up

"Below the line" means the reply scores at least three points worse than the position does overall. Replies played fewer than 25 times are left out: the sample is too small to read.

Is this costing you anything?

A table of averages cannot tell you whether you go wrong here — only your own games can. Opening Leak Lab reads your Chess.com or Lichess archive, finds the decisions you repeat, and checks each one against this book and a bundled Stockfish.

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