Source Lichess
White wins at least 4.1% more often than loses
At All Ratings, Semi-Slav Defense: Marshall Gambit, Forgotten Variation gives White a +4.1% minimum advantage (90% confidence). This gambit is effective.
| Rating | Min Adv | White Win | Draw | White Loss | Games |
|---|---|---|---|---|---|
| 0-999 | -20.0% | 50.4% | 0.9% | 48.7% | 55 |
| 1000-1199 | -3.9% | 51.6% | 6.9% | 41.5% | 137 |
| 1200-1399 | -4.5% | 50.8% | 3.7% | 45.5% | 285 |
| 1400-1599 | +4.5% | 53.6% | 4.1% | 42.3% | 570 |
| 1600-1799 | +6.8% | 54.1% | 3.0% | 42.9% | 1.3K |
| 1800-1999 | +0.4% | 49.5% | 4.2% | 46.3% | 3.2K |
| 2000-2199 | +0.5% | 48.3% | 6.1% | 45.6% | 5.7K |
| 2200-2499 | +2.8% | 48.5% | 8.1% | 43.4% | 5.3K |
| 2500+ | +7.6% | 41.6% | 28.1% | 30.3% | 1.8K |
The Semi-Slav Defense: Marshall Gambit, Forgotten Variation breaks at 0-999 overall (all time controls)—the first rating bracket where White no longer statistically wins more than loses. Below this rating, the gambit is viable for White. Note: breakpoints vary by time control—use the filters above for specific data.
The Semi-Slav Defense: Marshall Gambit, Forgotten Variation has a 48.6% (90% CI: 48.0%-49.2%) win rate for White overall, with a 8.1% draw rate and 43.3% loss rate. This is based on 18K games from Lichess.
The Semi-Slav Defense: Marshall Gambit, Forgotten Variation performs best at 2500+, where White has a minimum advantage of +7.6%. This means we're 90% confident White wins at least 7.6 percentage points more than they lose at this rating.
Blitz (+4.4% edge) outperforms Classical (+-17.7% edge) by 22.1 percentage points. Faster time controls typically favor gambits because opponents have less time to find accurate defenses.
Yes, significantly. Breakpoints by time control: Bullet: 1200-1399, Blitz: 1000-1199, Rapid: 1400-1599, Classical: Never. "Never" means the gambit remains viable through all rating brackets in that time control. Faster time controls typically extend viability.
The Semi-Slav Defense: Marshall Gambit, Forgotten Variation is very sharp with only 8.1% draws—91.9% of games end decisively. This makes it an excellent choice when you need to play for a win rather than accept a draw.
If you're below 0-999 overall, the Semi-Slav Defense: Marshall Gambit, Forgotten Variation is statistically favorable for White. Above that rating, opponents defend better and the gambit's edge disappears. Consider your typical opponents' level and the time control—faster games extend the gambit's viability.
As Black, the Semi-Slav Defense: Marshall Gambit, Forgotten Variation becomes easier to defend at 0-999 and above. Key principles: accept the material but develop quickly, castle early, trade pieces to reduce attacking potential, and return material at the right moment to neutralize the initiative. In faster time controls, the gambit is harder to defend—consider declining or transposing if you're not prepared.
This analysis is based on 18K games from Lichess. All statistics include 90% confidence intervals. Generally, 300+ games provide statistically meaningful results. Rating-specific and time-control-specific breakdowns have their own sample sizes shown in the table above.