Opening Leak Lab

Semi-Slav Defense

D43 1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 e6

White scores 53.9% here across 865 club games — but the 57.7% who answer Bg5 score 50.5%, 3 points worse.

What White actually plays here

Across 865 games from a Lichess-derived book of club play, White scores 53.9% in this position. These are the replies people choose, and how each one works out.

ReplyGamesShare White scoresVerdict
Bg5 499 57.7% 50.5% below the line
e3 154 17.8% 53.9% holds up
Bf4 75 8.7% 64.0% holds up
cxd5 55 6.4% 54.5% holds up
g3 48 5.5% 63.5% 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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