Queen's Gambit Declined: Semi-Slav, Koomen Variation
221 games from Lichess · Updated January 2026
Black expected score · All ratings · All speeds
65.5%
the worst score you would still get, 90% confident. At best 70.7%.
Measured over 221 games at this level and clock.
A strong choice for Black at this level and clock.
Outcomes for Black
Draw 7.4 · Score = win + ½ of the draws · 221 games
- Rank among the families Black can choose here
- not ranked — this is a variation, not a family
- Games in this context
- 221
- Best context
- not measured yet
- Average game length
- 37 moves
- Games that end decisively
- 92.6%
- Draws
- 7.4%
Best and worst are the strongest and weakest squares with at least 500 games behind them. The table further down shows every square, including thinner ones.
Where it holds · Black score by rating × clock
Green is clearly ahead for Black, grey is around even, red is behind. Tap a cell to measure there, and again to clear. It holds about the same all the way up, near 50.0%.
| Rating | UB | Bulle | Blitz | Rapid | Class |
|---|---|---|---|---|---|
| 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
- 1000-1199 rating, Blitz: 50.0% expected score (1 games)
- 1200-1399 rating, Bullet: 70.0% expected score (1 games)
- 1200-1399 rating, Blitz: 30.0% expected score (1 games)
- 1600-1799 rating, Blitz: 70.0% expected score (1 games)
- 1800-1999 rating, Bullet: 78.6% expected score (2 games)
- 1800-1999 rating, Blitz: 50.0% expected score (2 games)
- 1800-1999 rating, Rapid: 64.3% expected score (2 games)
- 2000-2199 rating, Bullet: 68.2% expected score (4 games)
- 2000-2199 rating, Blitz: 62.3% expected score (23 games)
- 2200-2499 rating, Bullet: 64.5% expected score (33 games)
- 2200-2499 rating, Blitz: 67.0% expected score (140 games)
- 2500+ rating, Bullet: 50.0% expected score (5 games)
- 2500+ rating, Blitz: 34.7% expected score (5 games)
- 2500+ rating, Rapid: 70.0% expected score (1 games)
Related Openings
Methodology
Across every rating and clock, the Queen's Gambit Declined: Semi-Slav, Koomen Variation scores 65.5% for Black — we are 90% confident the real figure is between 60.2% and 70.7% — from 221 Lichess games. Win rate, draw rate and loss rate come from games played December 2023 to November 2025.
How the figures are made
- Whose games these are
- 221+ rated games played on Lichess (2023-12 to 2025-11). The games are Lichess’s and free for anyone to use. What is ours is the reading of them. Last rebuilt January 2026.
- Which games we count
- Rated games only — nothing casual.
- Both players within 200 rating points of each other. A mismatch tells you about the gap, not about the opening.
- At least 2 moves played.
- A game is filed under White’s rating.
- Why every number comes with a range
- A number off a few hundred games is a guess. The same number off millions is a fact. The range is what tells them apart, and it is what the lists rank on — so an opening cannot reach the top on a lucky run of forty games. The more games behind a figure, the narrower its range.
- How much we need before we say anything
- An opening page needs 100 games. A gambit needs 50 games at a rating before we will say whether it pays there. The chaos and trap lists need 500 games overall and 250 games at one rating or clock.
Frequently Asked Questions
What is the Queen's Gambit Declined: Semi-Slav, Koomen Variation win rate?
Playing the Queen's Gambit Declined: Semi-Slav, Koomen Variation, Black wins 61.8%, draws 7.4% and loses 30.8%. Counting a draw as half a point, that is an Expected Score of 65.5%. It rests on 221 rated games from Lichess.
At what rating does the Queen's Gambit Declined: Semi-Slav, Koomen Variation perform best?
The Queen's Gambit Declined: Semi-Slav, Koomen Variation performs best for Black at 2200-2499, with an Expected Score of 66.6% (173 games) and the highest Floor of any rating with enough games to read.
How sharp is the Queen's Gambit Declined: Semi-Slav, Koomen Variation?
The Queen's Gambit Declined: Semi-Slav, Koomen Variation has a sharpness score of 92.6 (decisive), meaning 92.6% of games end decisively. Average game length is 37 moves.
What is the Queen's Gambit Declined: Semi-Slav, Koomen Variation win rate at 2200-2499?
At 2200-2499, Black wins 63.3%, draws 6.6% and loses 30.1%. Counting a draw as half a point, that is an Expected Score of 66.6%. It rests on 173 Lichess games, which average 37 moves.
What is the Queen's Gambit Declined: Semi-Slav, Koomen Variation win rate in Blitz?
In Blitz, Black wins 61.0%, draws 7.7% and loses 31.2%. Counting a draw as half a point, that is an Expected Score of 64.9%. It rests on 173 Lichess games.
Is the Queen's Gambit Declined: Semi-Slav, Koomen Variation a good opening?
The Queen's Gambit Declined: Semi-Slav, Koomen Variation is good for Black. Across all ratings, Black wins 61.8% of its games and loses 30.8%. It performs best at 2200-2499. Your results depend on your rating, time control, and how well you know the typical plans.