Sicilian Defense: O'Kelly Variation, Normal System, Cortlever Gambit
1. e4 c5 2. Nf3 a6 3. d4 cxd4 4. Bc4
The Sicilian Defense: O'Kelly Variation, Normal System, Cortlever Gambit is a chess opening classified as ECO B28, reached after 1. e4 c5 2. Nf3 a6 3. d4 cxd4 4. Bc4. It is a line of the Sicilian Defense. Black is to move.
In 12.6 million rated Lichess games (blitz and slower), this position was reached 53 times by this move order. White won 42%, 1% were drawn and Black won 57%. The most popular continuation is 4… e6 (47% of games).
Engine evaluation: +0.05 (Stockfish, depth 34; best line 4… Qc7 5. Bb3 e6 6. O-O Bc5 7. c3)
- ECO
- B28
- Moves
- 7 plies
- FEN
rnbqkbnr/1p1ppppp/p7/8/2BpP3/5N2/PPP2PPP/RNBQK2R b KQkq - 1 4- PGN
1. e4 c5 2. Nf3 a6 3. d4 cxd4 4. Bc4
Analyse with Stockfish · Board image (SVG) · Open on Lichess
Results by rating
| Average rating | Games | White / draw / Black |
|---|---|---|
| 0-1499 | 13 | |
| 1500-1999 | 34 | |
| 2000+ | 6 | |
| All | 53 |
Most played moves
| Move | Games | White / draw / Black |
|---|---|---|
| 4… e6 | 25 (47%) | |
| 4… Nc6 | 11 (21%) | |
| 4… Nf6 | 6 (11%) | |
| 4… b5 | 5 (9%) | |
| 4… e5 | 2 (4%) | |
| 4… Qc7 | 1 (2%) | |
| 4… h6 | 1 (2%) | |
| 4… d6 | 1 (2%) |
Master games
2 over-the-board games are classified under this line (White 0%, draw 0%, Black 100%). The strongest:
- WIM Alicja Sliwicka (2311) – Artak Manukian (2196) 0-1 · Speed Chess Super Swiss · 2020-10-03
- Jozsef Reiz (1634) – IM Dan Bogdan (2366) 0-1 · Tasnad Open 2018 · 2018-09-11
Highest-rated Lichess games
- Ugodev (2242) – NEWNIKITOV2026 (2291) 0-1 · 2026-09-06 · 180 + 0s
- stupidilusions (2080) – Alphachofy (2201) 0-1 · 2026-09-06 · 180 + 2s
- gardalutim_07 (2144) – Mael_sulo83 (2040) 0-1 · 2026-09-04 · 420 + 3s
Comes from
Sicilian Defense: O'Kelly Variation, Normal System 1. e4 c5 2. Nf3 a6 3. d4
More Sicilian Defense lines (all)
- Sicilian Defense (1. e4 c5) B20
- Sicilian Defense: Amazon Attack B20
- Sicilian Defense: Big Clamp Formation B20
- Sicilian Defense: Bowdler Attack B20
- Sicilian Defense: Brick Variation B20
- Sicilian Defense: Czerniak Attack B20
- Sicilian Defense: Czerniak Attack, Queen Fianchetto Variation B20
- Sicilian Defense: Euwe Attack, Prins Gambit B20
- Sicilian Defense: Gloria Variation B20
- Sicilian Defense: Grob Variation B20
- Sicilian Defense: Keres Variation B20
- Sicilian Defense: King David's Opening B20
Opening names and moves from the Lichess openings dataset; statistics from the Lichess open database, 2026-09 (CC0), sample of 12.6 million games, bots excluded; evaluations from Lichess cloud analysis (all CC0). Master games from The Week in Chess #920–#1664 by Mark Crowther, used with permission.