Opening Leak Lab

Slav Defense: Three Knights Variation

D15 1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3

Black scores 40.0% here across 429 club games — but the 16.6% who answer Bg4 score 36.6%, 3 points worse.

What Black actually plays here

Across 429 games from a Lichess-derived book of club play, Black scores 40.0% in this position. These are the replies people choose, and how each one works out.

ReplyGamesShare Black scoresVerdict
e6 147 34.3% 39.1% holds up
Bf5 99 23.1% 42.4% holds up
Bg4 71 16.6% 36.6% below the line
g6 36 8.4% 47.2% holds up
dxc4 35 8.2% 35.7% below the line

"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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