Ruy Lopez by rating
1.e4 e5 2.Nf3 Nc6 3.Bb5
The Ruy Lopez is the deepest studied opening in chess, and it is the one place in this dataset where knowing more makes you match the engine less. After 3.Bb5 Stockfish likes Nf6, but the move that theory teaches is a6, and stronger players play the theory.
How often each rating finds the engine move
Findability falls as rating rises, 28 percent at 1000 down to 15 percent at 2200. That is a repertoire choice, not a mistake.
The position after 1.e4 e5 2.Nf3 Nc6 3.Bb5
This is where the opening actually starts asking a question. 30 moves are legal; Stockfish scores every one of them at depth 20.
Stockfish plays Nf6 at -0.29. Its next two choices are a6 (-0.35) and Bc5 (-0.50).
| Rating | Most likely human move | Finds Nf6 | Cost in pawns |
|---|---|---|---|
| 1000 | Nf6-0.29 | 28% | same move |
| 1200 | Nf6-0.29 | 24% | same move |
| 1400 | d6-0.77 | 19% | 0.48 |
| 1600 | d6-0.77 | 16% | 0.48 |
| 1800 | a6-0.35 | 15% | 0.06 |
| 2000 | a6-0.35 | 16% | 0.06 |
| 2200 | a6-0.35 | 15% | 0.06 |
Two plies deeper
Following the most popular human continuation at 1400: d6 (24%), then Bxc6+ (27%).
Stockfish plays bxc6 at -0.32. Its next two choices are Bd7 (-4.56) and Ke7 (-5.11).
| Rating | Most likely human move | Finds bxc6 | Cost in pawns |
|---|---|---|---|
| 1000 | bxc6-0.32 | 97% | same move |
| 1200 | bxc6-0.32 | 99% | same move |
| 1400 | bxc6-0.32 | 99% | same move |
| 1600 | bxc6-0.32 | 99% | same move |
| 1800 | bxc6-0.32 | 99% | same move |
| 2000 | bxc6-0.32 | 99% | same move |
| 2200 | bxc6-0.32 | 99% | same move |
See this for your own games
Chessdrive runs the same two engines on your phone. It shows the move you should have found at your rating, not just the move a 3500-rated engine would have played.
How these numbers were produced
Stockfish 18 by the Stockfish developers (see AUTHORS file) at depth 20, with MultiPV set to the exact legal move count of each position so no move is left unscored, and Maia3, chessformer, human move prediction, 5m (bundled with maia3-js, UofTCSSLab/Maia3-5M, about 5M parameters) for the human move distribution. Run on 2026-08-29 over 28 positions across 7 rating bands. Findability is Maia3's probability for Stockfish's top move; it is not a claim about win rate.