Mistake Review
When you get a puzzle wrong, that's your biggest opportunity for improvement. Mistake Review uses spaced repetition to ensure you see those puzzles again at optimal intervals until you truly master them.
The Problem with Mistakes
The woodpecker method is powerful for building pattern recognition. But in a typical first cycle, users average around 80% accuracy, meaning roughly 1 in 5 puzzles is missed. At tournament difficulty, that number climbs closer to 50%. Those are exactly the patterns your brain hasn't locked in yet.
Without a system, those missed puzzles just disappear into the next cycle. You might see them again, but by then you've forgotten why you got them wrong. The same mistakes repeat.
The Woodpecker Method is a trademark licensed by Chess.com, LLC and Quality Chess UK LTD, originating from GM Hans Tikkanen. Disco Chess is not affiliated with, endorsed by, or connected to Chess.com, Quality Chess, or Chessable.
How Mistake Review Works
When you get a puzzle wrong in any puzzle set, it's immediately added to your Mistake Review queue. From there, it follows a 5-level progression:
Level 1: 1 day
Just added. You'll see it again tomorrow. These are your hardest items -- data shows just 11.9% first-attempt accuracy on puzzles stuck at this level.
Level 2: 3 days
Got it right once. Building the pattern. Items here show about 89.7% accuracy -- the first correct solve is the biggest hurdle.
Level 3: 7 days
Halfway to mastery. Accuracy holds steady around 90.4%, and solve times are dropping as the pattern becomes more familiar.
Level 4: 14 days
Almost there. At 91.6% accuracy, you're proving the pattern sticks even over two weeks.
Level 5: 30 days
Final test. Items that reach this level show 95.2% accuracy -- genuinely mastered. Solve it correctly and it's cleared for good.
Solve correctly
Advance to the next level with a longer interval.
Get it wrong
Reset to Level 1 and try again tomorrow.
Why These Specific Intervals?
The 1, 3, 7, 14, and 30-day intervals aren't arbitrary. They're based on decades of research into the "spacing effect," which shows that reviewing at increasing intervals produces significantly better long-term retention than massed practice. Our data confirms it: items recalled after a 5-15 day gap show 96.3% retention on their next review, compared to 94.9% for items reviewed after just 2-5 days. Longer gaps make retrieval harder in the moment, which strengthens the memory trace.
You're not grinding the same puzzle every day. You're reviewing it exactly when your brain needs the reinforcement, just before you'd forget it.
And if life gets in the way, don't stress. Our analysis of 115,000+ review attempts shows that missing a scheduled review by a day or two isn't catastrophic. For items you've previously solved correctly, retention stays above 90% even when you review later than scheduled. The intervals have built-in slack.
Want to learn more about the science?
Read our in-depth guide on Spaced Repetition for Chess to understand the forgetting curve, the research behind optimal intervals, and why this technique is so effective for pattern retention.
Two Sources of Review Items
Your review queue is populated from two sources, and they behave very differently:
Puzzle Set Mistakes
Every puzzle you get wrong in any puzzle set is automatically added to your review queue. Standard puzzle reviews have 89.6% accuracy overall, and 8.8% of items reach full mastery (Level 5).
Missed Tactics from Your Games
Connect your Lichess or Chess.com account, and we'll find tactics you missed in your actual games. These are significantly harder: 59.4% accuracy vs 89.6% on standard puzzles. Only 1.6% reach mastery. But the learning curve is steep -- accuracy climbs from 49.3% on first review to 76.0% by the 7th.
Learn more →Cycle-based repetition + Anki-style review = complete training
Disco Chess gives you the best of both worlds. And the data shows they work better together: users who completed 200+ mistake reviews gained +9.8 percentage points in accuracy between cycles, compared to +5.4pp for users who skipped reviews entirely. Heavy reviewers started with the lowest cycle 1 accuracy (80.6%) but converged to 90.4% -- matching or exceeding everyone else.
Cycle-based training
Build speed and pattern recognition across entire puzzle sets. Massed practice builds automatic recognition.
Learn more →Anki-Style Mistake Review
Target your actual weaknesses with spaced repetition. Locks patterns into long-term memory. The review system is most valuable for users who make more mistakes initially -- exactly when there's the most material to work with.
Frequently Asked Questions
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