Opening Leak Lab

Modern Defense: Averbakh System

A42 1. d4 g6 2. c4 Bg7 3. Nc3 d6 4. e4

Black scores 53.0% here across 430 club games — but the 17.2% who answer Nc6 score 48.0%, 5 points worse.

What Black actually plays here

Across 430 games from a Lichess-derived book of club play, Black scores 53.0% in this position. These are the replies people choose, and how each one works out.

ReplyGamesShare Black scoresVerdict
Nf6 186 43.3% 56.5% holds up
Nc6 74 17.2% 48.0% below the line
Nd7 54 12.6% 59.3% holds up
c6 36 8.4% 38.9% below the line
e5 26 6.0% 53.8% 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.

Analyse my games