Petrov's Defense: Three Knights Game
Chess opening · ECO C42 · 5 half-moves
1. e4 e5 2. Nf3 Nf6 3. Nc3
The Petrov's Defense: Three Knights Game is reached after 1. e4 e5 2. Nf3 Nf6 3. Nc3. It is Black's move in the position shown.
It branches from the Petrov's Defense with 3. Nc3.
How often it is played
The Petrov's Defense: Three Knights Game and its variations appeared in 0.34% of games — 10,262 of 3,000,000 rated games sampled from Lichess in September 2026. That makes it number 126 of the openings listed here.
Results
White won 50%, 3.8% were drawn and Black won 46%. These are games between players of every strength and time control, so they say how the opening does in practice rather than how sound it is.
What the engine thinks
Stockfish, at depth 18, evaluates the position at +0.10 — which is level. Positive numbers favour White; see reading the evaluation bar.
Similar openings
The most-played alternatives — what else could have been chosen around the move where this opening begins.
| Opening | Moves | Share of games |
|---|---|---|
| Petrov's Defense: Italian Variation | 1. e4 e5 2. Nf3 Nf6 3. Bc4 | 0.27% |
| King's Knight Opening: Normal Variation | 1. e4 e5 2. Nf3 Nc6 | 10% |
| Philidor Defense | 1. e4 e5 2. Nf3 d6 | 2.1% |
Main continuations
| Variation | Moves | Share of games |
|---|---|---|
| Four Knights Game: Spanish Variation, Rubinstein Variation, Henneberger Variation | 1. e4 e5 2. Nf3 Nf6 3. Nc3 Nc6 4. Bb5 Nd4 5. O-O | 0.00% |
| Four Knights Game: Spanish Variation, Gunsberg Counterattack | 1. e4 e5 2. Nf3 Nf6 3. Nc3 Nc6 4. Bb5 Bb4 5. O-O O-O 6. Nd5 Nxd5 7. exd5 e4 | 0.00% |
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