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Alekhine Defense: O'Sullivan Gambit

109K games from Lichess · Updated January 2026

Key Finding

Alekhine Defense: O'Sullivan Gambit gives Black a 55.3% expected score — a strong choice.

Worst case (90% confidence) you keep a 10.0% advantage over the 50% baseline.

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Rating
Time
Black Expected Score55.3%Based on 109K gamesWin + ½×draw — predicts rating gain better than win rate
45%55.3%60%
Range (90% confident): 55.0% – 55.5%
Min adv+10.0%
ContextAll ratings · All speeds · n=109K
Outcome Distribution
3...b5
Alekhine Defense: O'Sullivan Gambit
Analyzen=109K
Avg Length30 moves
Sharpness97%
Draw Rate2.9%

Sharpness — share of games that end decisively

What is the Alekhine Defense: O'Sullivan Gambit expected score for Black?

Snapshot

At all ratings, the Alekhine Defense: O'Sullivan Gambit has a 55.3% expected score for Black (we're 90% confident it's between 55.0% and 55.5%), based on 109K Lichess games.

Extra Analysis

Deep-dive datasets for this opening

Gambit BreakpointBlack

Peak: +11.4% · Breakpoint: 0-999

Black Win% by Rating

Declines with rating: 51% → 47%

0
1000
1200
1400
1600
1800
2000
2200
2500+

  • 0-999: 50.9% win rate (882 games)
  • 1000-1199: 54.2% win rate (2,512 games)
  • 1200-1399: 54.1% win rate (6,270 games)
  • 1400-1599: 55.7% win rate (13,717 games)
  • 1600-1799: 55.3% win rate (24,554 games)
  • 1800-1999: 54.9% win rate (28,812 games)
  • 2000-2199: 52.0% win rate (23,697 games)
  • 2200-2499: 47.4% win rate (6,423 games)
  • 2500+: 46.8% win rate (1,637 games)

Black Win% by Time Control

Best in Bullet (55%), worst in UltraBullet (40%)

UltraBullet
Bullet
Blitz
Rapid
Classical

  • UltraBullet: 39.7% win rate (30 games)
  • Bullet: 54.5% win rate (33,030 games)
  • Blitz: 53.9% win rate (63,102 games)
  • Rapid: 51.6% win rate (11,719 games)
  • Classical: 46.4% win rate (623 games)

Black% by Rating × Time Control

Click any cell to filter — click it again to clear. Green = above 50%, Red = below 50%.

RatingUBBulleBlitzRapidClass
0-999—
1000-1199
1200-1399
1400-1599
1600-1799
1800-1999
2000-2199—
2200-2499—
2500+———

Expected score matrix by rating bracket and time control

  • 0-999 rating, UltraBullet: 50.0% expected score (2 games)
  • 0-999 rating, Bullet: 57.3% expected score (439 games)
  • 0-999 rating, Blitz: 51.1% expected score (346 games)
  • 0-999 rating, Rapid: 29.8% expected score (95 games)
  • 1000-1199 rating, UltraBullet: 61.2% expected score (3 games)
  • 1000-1199 rating, Bullet: 55.9% expected score (1,062 games)
  • 1000-1199 rating, Blitz: 54.9% expected score (1,238 games)
  • 1000-1199 rating, Rapid: 54.2% expected score (203 games)
  • 1000-1199 rating, Classical: 23.4% expected score (6 games)
  • 1200-1399 rating, UltraBullet: 50.0% expected score (12 games)
  • 1200-1399 rating, Bullet: 56.7% expected score (1,868 games)
  • 1200-1399 rating, Blitz: 55.3% expected score (3,474 games)
  • 1200-1399 rating, Rapid: 53.1% expected score (894 games)
  • 1200-1399 rating, Classical: 41.5% expected score (22 games)
  • 1400-1599 rating, UltraBullet: 14.0% expected score (11 games)
  • 1400-1599 rating, Bullet: 56.0% expected score (4,446 games)
  • 1400-1599 rating, Blitz: 57.6% expected score (7,309 games)
  • 1400-1599 rating, Rapid: 56.1% expected score (1,921 games)
  • 1400-1599 rating, Classical: 35.8% expected score (30 games)
  • 1600-1799 rating, UltraBullet: 70.0% expected score (1 games)
  • 1600-1799 rating, Bullet: 55.3% expected score (6,312 games)
  • 1600-1799 rating, Blitz: 57.7% expected score (14,730 games)
  • 1600-1799 rating, Rapid: 53.8% expected score (3,264 games)
  • 1600-1799 rating, Classical: 55.4% expected score (247 games)
  • 1800-1999 rating, UltraBullet: 70.0% expected score (1 games)
  • 1800-1999 rating, Bullet: 56.8% expected score (7,799 games)
  • 1800-1999 rating, Blitz: 56.8% expected score (17,648 games)
  • 1800-1999 rating, Rapid: 54.4% expected score (3,087 games)
  • 1800-1999 rating, Classical: 48.4% expected score (277 games)
  • 2000-2199 rating, Bullet: 55.4% expected score (7,248 games)
  • 2000-2199 rating, Blitz: 53.3% expected score (14,424 games)
  • 2000-2199 rating, Rapid: 51.5% expected score (1,986 games)
  • 2000-2199 rating, Classical: 30.3% expected score (39 games)
  • 2200-2499 rating, Bullet: 54.6% expected score (2,660 games)
  • 2200-2499 rating, Blitz: 46.4% expected score (3,492 games)
  • 2200-2499 rating, Rapid: 42.2% expected score (269 games)
  • 2200-2499 rating, Classical: 50.0% expected score (2 games)
  • 2500+ rating, Bullet: 50.4% expected score (1,196 games)
  • 2500+ rating, Blitz: 44.9% expected score (441 games)

Related Openings

Parent
Alekhine Defense
50.7%
Variations (5)
Alekhine Defense: Scandinavian Variation
47.1%
Alekhine Defense: Maróczy Variation
49.0%
Alekhine Defense: Normal Variation
49.9%
Alekhine Defense: Exchange Variation
47.4%
Alekhine Defense: Scandinavian Variation, Geschev Gambit
47.6%
Analyze Alekhine Defense: O'Sullivan Gambit PositionsGet move-by-move win rates at your level with the TrueElo analyzer

Frequently Asked Questions

What is the Alekhine Defense: O'Sullivan Gambit win rate?

The Alekhine Defense: O'Sullivan Gambit has a 43.3% (90% CI: 43.1%-43.6%) win rate for white, based on 109K rated games from Lichess.

At what rating does the Alekhine Defense: O'Sullivan Gambit perform best?

The Alekhine Defense: O'Sullivan Gambit performs best at 2200-2499 Elo with a 48.2% win rate for white (6.4K games). Win rate tends to decline at higher ratings as opponents know the theory better.

Is the Alekhine Defense: O'Sullivan Gambit better in blitz or rapid?

Classical (48.8%) outperforms Blitz (43.0%) by 5.8%. Choose your time control wisely.

How sharp is the Alekhine Defense: O'Sullivan Gambit?

The Alekhine Defense: O'Sullivan Gambit has a sharpness score of 97.1 (very decisive), meaning 97.1% of games end decisively. Average game length is 30 moves.

What is the Alekhine Defense: O'Sullivan Gambit win rate at 0-999 Elo?

At 0-999 Elo, the Alekhine Defense: O'Sullivan Gambit has a 47.3% (90% CI: 44.5%-50.0%) win rate for white, based on 882 Lichess games. Average game length is 23 moves with a 1.9% draw rate.

What is the Alekhine Defense: O'Sullivan Gambit win rate at 1000-1199 Elo?

At 1000-1199 Elo, the Alekhine Defense: O'Sullivan Gambit has a 43.7% (90% CI: 42.1%-45.4%) win rate for white, based on 2.5K Lichess games. Average game length is 25 moves with a 2.1% draw rate.

What is the Alekhine Defense: O'Sullivan Gambit win rate at 1200-1399 Elo?

At 1200-1399 Elo, the Alekhine Defense: O'Sullivan Gambit has a 43.5% (90% CI: 42.5%-44.5%) win rate for white, based on 6.3K Lichess games. Average game length is 27 moves with a 2.4% draw rate.

What is the Alekhine Defense: O'Sullivan Gambit win rate at 1400-1599 Elo?

At 1400-1599 Elo, the Alekhine Defense: O'Sullivan Gambit has a 42.1% (90% CI: 41.4%-42.8%) win rate for white, based on 14K Lichess games. Average game length is 28 moves with a 2.2% draw rate.

What is the Alekhine Defense: O'Sullivan Gambit win rate at 1600-1799 Elo?

At 1600-1799 Elo, the Alekhine Defense: O'Sullivan Gambit has a 42.3% (90% CI: 41.8%-42.8%) win rate for white, based on 25K Lichess games. Average game length is 29 moves with a 2.4% draw rate.

What is the Alekhine Defense: O'Sullivan Gambit win rate at 1800-1999 Elo?

At 1800-1999 Elo, the Alekhine Defense: O'Sullivan Gambit has a 42.1% (90% CI: 41.7%-42.6%) win rate for white, based on 29K Lichess games. Average game length is 30 moves with a 2.9% draw rate.

What is the Alekhine Defense: O'Sullivan Gambit win rate at 2000-2199 Elo?

At 2000-2199 Elo, the Alekhine Defense: O'Sullivan Gambit has a 44.5% (90% CI: 44.0%-45.0%) win rate for white, based on 24K Lichess games. Average game length is 31 moves with a 3.5% draw rate.

What is the Alekhine Defense: O'Sullivan Gambit win rate at 2200-2499 Elo?

At 2200-2499 Elo, the Alekhine Defense: O'Sullivan Gambit has a 48.2% (90% CI: 47.2%-49.2%) win rate for white, based on 6.4K Lichess games. Average game length is 33 moves with a 4.5% draw rate.

What is the Alekhine Defense: O'Sullivan Gambit win rate at 2500+ Elo?

At 2500+ Elo, the Alekhine Defense: O'Sullivan Gambit has a 49.0% (90% CI: 46.9%-51.0%) win rate for white, based on 1.6K Lichess games. Average game length is 37 moves with a 4.2% draw rate.

What is the Alekhine Defense: O'Sullivan Gambit win rate in Bullet?

In Bullet games, the Alekhine Defense: O'Sullivan Gambit has a 43.3% (90% CI: 42.8%-43.7%) win rate for white (33K Lichess games). Draw rate is 2.2%.

What is the Alekhine Defense: O'Sullivan Gambit win rate in Blitz?

In Blitz games, the Alekhine Defense: O'Sullivan Gambit has a 43.0% (90% CI: 42.7%-43.3%) win rate for white (63K Lichess games). Draw rate is 3.1%.

What is the Alekhine Defense: O'Sullivan Gambit win rate in Rapid?

In Rapid games, the Alekhine Defense: O'Sullivan Gambit has a 44.8% (90% CI: 44.1%-45.6%) win rate for white (12K Lichess games). Draw rate is 3.6%.

What is the Alekhine Defense: O'Sullivan Gambit win rate in Classical?

In Classical games, the Alekhine Defense: O'Sullivan Gambit has a 48.8% (90% CI: 45.5%-52.0%) win rate for white (623 Lichess games). Draw rate is 4.9%.

Is the Alekhine Defense: O'Sullivan Gambit a good opening?

The Alekhine Defense: O'Sullivan Gambit is slightly favors black with a 43.3% (90% CI: 43.1%-43.6%) win rate across all ratings. It performs best at 2200-2499 Elo. Your results depend on your rating, time control, and how well you know the typical plans.