Petrov's Defense
C42 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4
White scores 56.5% here across 2,386 club games — but the 10.1% who answer d3 score 43.1%, 13 points worse.
What White actually plays here
Across 2,386 games from a Lichess-derived book of club play, White scores 56.5% in this position. These are the replies people choose, and how each one works out.
| Reply | Games | Share | White scores | Verdict |
|---|---|---|---|---|
| Nc3 | 863 | 36.2% | 58.3% | holds up |
| Nxe5 | 695 | 29.1% | 60.3% | holds up |
| Bc4 | 299 | 12.5% | 54.0% | holds up |
| d3 | 240 | 10.1% | 43.1% | below the line |
| d4 | 230 | 9.6% | 59.1% | 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.