Zukertort Opening: Black Mustang Defense
A04 1. Nf3 Nc6
White scores 58.4% here across 424 club games — but the 15.1% who answer Nc3 score 36.7%, 22 points worse.
What White actually plays here
Across 424 games from a Lichess-derived book of club play, White scores 58.4% in this position. These are the replies people choose, and how each one works out.
| Reply | Games | Share | White scores | Verdict |
|---|---|---|---|---|
| d4 | 196 | 46.2% | 64.3% | holds up |
| Nc3 | 64 | 15.1% | 36.7% | below the line |
| g3 | 53 | 12.5% | 57.5% | holds up |
| e4 | 47 | 11.1% | 67.0% | holds up |
| c4 | 34 | 8.0% | 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.