Sicilian Defense: Big Clamp Formation
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Statistics from Lichess
62,370 games: White 50.8% / Draw 4.1% / Black 45.0%
| Next move | Games | White / Draw / BlackW / D / B |
|---|---|---|
| 20,18820K | ||
| 19,24919K | ||
| 9,2029,202 | ||
| 7,2077,207 | ||
| 1,7711,771 | ||
| 1,2281,228 | ||
| 592592 | ||
| 462462 |
Rated Lichess games between players rated 1600 to 2500, from the Lichess opening explorer, updated Nov 3, 2026
Engine evaluation
+0.05 The position is about equal
Best play: 4... Nf6 5. Be2 g6 6. Nf3 Bg7 7. a4 e5 8. O-O O-O 9. Na3
Stockfish 19, depth 30, after the line's last move. Scores are in pawns, from White's side.
Overview
Sicilian Defense: Big Clamp Formation (ECO B20, Semi-Open Games) is a variation of the Sicilian Defense, reached after 1. e4 c5 2. d3 Nc6 3. c3 d6 4. f4 (4 moves).
In 62,370 rated Lichess games between players rated 1600 to 2500, White won 50.8%, Black 45.0% and 4.1% were drawn. Black's most played move here is 4…Nf6, in 32% of those games.
Written from the Lichess opening list and explorer. Know this line well? Write about it.
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How to play against the Sicilian Defense: Big Clamp Formation
4…g6 scores best for Black: 48.8%, with Black winning 46.8% and White 49.2% of 19K games. The most played, 4…Nf6, scores 46.7% in 20K games, and 4…e6 scores lowest: 46.0%. Stockfish's first choice is 4…Nf6.
Main answers: those played in at least 5% of these games. Score: Black's wins plus half the draws, in rated Lichess games between players rated 1600 to 2500. How to play against other popular openings
Cite this page
Caissa Codex. “Sicilian Defense: Big Clamp Formation (B20)”. Lichess data as of 3 Nov 2026. https://chesscodex.org/openings/sicilian-defense-big-clamp-formation