Opening Leak Lab

Sicilian Defense: O'Kelly Variation

B28 1. e4 c5 2. Nf3 a6

White scores 51.9% here across 621 club games — but the 14.2% who answer Bc4 score 44.9%, 7 points worse.

What White actually plays here

Across 621 games from a Lichess-derived book of club play, White scores 51.9% in this position. These are the replies people choose, and how each one works out.

ReplyGamesShare White scoresVerdict
d4 268 43.2% 51.7% holds up
c3 94 15.1% 48.9% holds up
Bc4 88 14.2% 44.9% below the line
Nc3 56 9.0% 56.2% holds up
c4 34 5.5% 58.8% 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.

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