London System by rating
1.d4 d5 2.Bf4
The London System is the most popular d4 opening below 1800 and the most misunderstood position on this page. Against 2.Bf4 the engine's answer is the immediate c5 strike, and almost nobody plays it at any level: at 1000 the likeliest reply is Nc6, and it costs about a third of a pawn.
How often each rating finds the engine move
3 percent at 1000, 14 percent at 2200. The London is easy to play and hard to answer well.
The position after 1.d4 d5 2.Bf4
This is where the opening actually starts asking a question. 27 moves are legal; Stockfish scores every one of them at depth 20.
Stockfish plays c5 at -0.12. Its next two choices are Bf5 (-0.20) and Nf6 (-0.22).
| Rating | Most likely human move | Finds c5 | Cost in pawns |
|---|---|---|---|
| 1000 | Nc6-0.42 | 3% | 0.30 |
| 1200 | Nc6-0.42 | 4% | 0.30 |
| 1400 | Nc6-0.42 | 5% | 0.30 |
| 1600 | Nf6-0.22 | 6% | 0.10 |
| 1800 | Nf6-0.22 | 7% | 0.10 |
| 2000 | Nf6-0.22 | 9% | 0.10 |
| 2200 | Nf6-0.22 | 14% | 0.10 |
Two plies deeper
Following the most popular human continuation at 1400: Nc6 (29%), then e3 (59%).
Stockfish plays Nf6 at -0.43. Its next two choices are e6 (-0.48) and Bf5 (-0.53).
| Rating | Most likely human move | Finds Nf6 | Cost in pawns |
|---|---|---|---|
| 1000 | Nf6-0.43 | 39% | same move |
| 1200 | Nf6-0.43 | 38% | same move |
| 1400 | Nf6-0.43 | 35% | same move |
| 1600 | Bf5-0.53 | 33% | 0.10 |
| 1800 | Bf5-0.53 | 31% | 0.10 |
| 2000 | Bf5-0.53 | 31% | 0.10 |
| 2200 | Bf5-0.53 | 32% | 0.10 |
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.