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Play
Start a quick game against Stockfish and save the full PGN.
Research preview · nFactorial Incubator 2026
Turn every blunder into your next training plan.
BlunderLab reviews your games, explains mistakes in plain language, detects recurring patterns, and gives you one clear goal for the next match.
- AI Coach explains every blunder
- Daily Blunder from your own games
- EN / RU coach
Product walkthrough
See the learning loop before you play.
A compact preview of the path BlunderLab is built around: play, review the critical moment, carry one goal into the next game.
The gap
Engine feedback tells you the move. BlunderLab tells you the habit.
“I lost, but I still do not know what I should learn.”
Engine
Typical review: a red mark, a best move, and no next step.
BlunderLab
BlunderLab: three moments, one recurring pattern, one training goal.
How it works
A simple loop after every game.
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Review
Stockfish finds the moments where the evaluation changed.
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Pattern
The AI Coach maps each mistake to one of eight thinking patterns.
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Train
You leave with one clear goal and a daily puzzle from your own games.
Blunder taxonomy
Eight patterns that explain how beginners actually lose.
Engine analysis tells you what was wrong. BlunderLab tells you which thinking habit caused it.
Featured pattern
Tunnel Vision
The pattern most beginners face — and the one we anchor every review around.
You're following your plan. Your opponent quietly threatens something else. You don't see it because you stopped looking. The fix isn't tactics — it's a habit of glancing at the whole board before every move.
- Trigger
- Two or three moves into a clear plan.
- Habit
- Before each move, scan opponent's last move and active threats.
Seven more patterns
- 02
Hanging Piece
You left a piece undefended.
- 03
Missed Tactic
A forcing line was on the board.
- 04
King Safety
You weakened your king or ignored a mating threat.
- 05
Greedy Move
You grabbed material and lost the position.
- 06
Time Panic
The move looks like it was made too fast.
- 07
Opening Drift
Early deviation from sound development.
- 08
Endgame Technique
A more precise endgame method existed.
Each tag is a thinking habit, not a chess move.
Progress
Your dashboard tracks weaknesses, streak, Daily Blunder, and city rank.
- Tunnel Vision
- Top weakness
- 4d
- Streak
- #12
- City rank
- Ready
- Daily Blunder
Yesterday you missed this fork. Can you find it today?
Daily Blunder turns your old mistake into a personal puzzle.
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Pricing teaser
Free proves the loop. Pro unlocks depth.
Free
$0
- 3 reviews/day
- AI Coach chat (3/day)
- Classic Game
- Daily Blunder
Pro
$4.99/mo
- Unlimited reviews
- AI Coach chat (20/day)
- Pattern Drill
- Deep Review
School
Custom
- Student dashboard
- Unlimited AI Coach chat
- Class leaderboard
- Coach view
Start your first review.
Play one game, let the coach explain the critical moments, then take one goal into the next match.