A chess coach built from your games
Stop losing the same game twice.
Type your username and the coach reads your recent games, names the mistake you keep repeating, and turns it into tomorrow’s training.
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50 games reviewed
ExampleYour repeated leak: pieces left undefended once the attack cools.
Tomorrow’s plan: 5 targeted positions from these games.
Qd2 lost the bishop: its only defender walked away. The same leak shows up in nine of these fifty games.
50 games reviewed
ExampleYour repeated leak: pieces left undefended once the attack cools.
Tomorrow’s plan: 5 targeted positions from these games.
Qd2 lost the bishop: its only defender walked away. The same leak shows up in nine of these fifty games.
No signup to start
Type a username, read the result.
A verdict on every move
Full game reviews, free — no daily cap.
A plan every morning
Built from your games, not a syllabus.
Free while it's in beta
All of it. You'll know before that changes.
The mistake you keep making has a name
The coach replays your games with Stockfish and re-checks every suspect moment at higher depth before it counts. Then it looks across the batch: not “you blundered here” but “this is the kind of blunder you make.”
Last games, gradedExample
- Lvs mira_endgames 1548blitz · Two Knights Defense · 22 moves!!??2×?
- Wvs kingwalk_pete 1502rapid · Danish Gambit Accepted · 27 moves!!?
- Dvs rook_before_dark 1521blitz · Caro-Kann Defense · 41 moves?
?? 17.Qd2 in the first loss: the queen was the c4 bishop’s only defender, and Bxc4 takes it for free.
Confirmed at higher depth, filed under the leak it belongs to: pieces left undefended once the attack cools. That pattern, not the single move, is what gets trained.
The review becomes tomorrow’s work
Most sites stop at the report. Here every confirmed mistake comes back as a position with the continuation hidden. Find the move you missed and it is fixed — retired from the queue for good.
A backlog of seventy blunders is meant to shrink, not to become flashcards.
From your games · position 1 of 5Example
Move 17 against mira_endgames. The knight hits your queen. This time, find the retreat that keeps the edge.
The continuation stays hidden until you commit a move. Solve it clean and this position never comes back.
One short session a day
Every morning the coach sets a session from what the evidence flags: the opening line you keep fumbling, the tactic you keep missing, the blunder waiting to be repaired.
Tomorrow’s sessionExample
- 1Opening practiceTwo Knights: the knight attack, recalled from memory
- 2From your gamesRepair the Qd2 blunder vs mira_endgames
- 3TacticsFive hanging-piece puzzles, chosen for the leak
The rooms the plan draws from — all of them open for self-directed work whenever you want more.
Free while it’s in beta
One plan while the product is in beta. It costs nothing.
Full beta access
$0/ month
Everything in Blunderproof is free while the product is in beta.
Future standard price: $4.99/month. You will be told before anything changes.
- Unlimited game diagnosis
- Personalized daily training
- Mistake review and opening practice
- History, trends, and deep-dive analysis
- Progress saved with a free account
Existing reports, learned positions, and exported data will never be held hostage by a later plan change.
See what the coach finds in your games
New openings, exercises, and annotated games are added steadily, and your plan picks up whatever fits your play.