Never lose the same way twice.
We find the move that cost you the game and turn it into a puzzle you drill until it sticks.
You played Qh5 but Nf3 was stronger.
Qh5 develops the queen too early. Black plays Nf6 with tempo, and after the queen retreats Black is comfortably ahead in development. Nf3 develops and keeps the game level.
Example. From a real game, analyzed once and shown to every visitor.
Small because we're new. We'd rather show the real number than a made-up one.
Drill your mistakes. Repeat until it sticks.
Every move you miss becomes a puzzle in your review queue: tactics you failed in practice and blunders from your own games. You solve it, rate how hard it felt, and the schedule decides when you see it next. Shaky ones return tomorrow. Solid ones space out over weeks. When the queue is clear, you're done for the day.
Example. Your real counts live in the app.
How easy was this puzzle?
Generic trainers drill someone else's puzzles. This one drills yours.
Your queue mixes two sources on one schedule: tactics puzzles you failed in practice, and blunders pulled straight from your own games. The ones from your games keep the opponent and date, so you're re-solving a real moment instead of an abstract position. Want to work a weakness? Filter the queue down to just your own mistakes.
Practice abstract tactics and replay the exact moment you lost. Same queue, same schedule. Filter to your own games in the Review Queue, or drill a specific weakness from your Weaknesses page.
Open the app. Do today's plan. Close the app.
We sync overnight
Link your chess account once and each night we pull your new games and run engine analysis on them, flagging the moves that cost you material or the game. No account? Drop in a PGN instead.
You get a plan, not a to-do list
Pick 15, 30, or 60 minutes. We build the session for you: review queue first, then a weakness drill or opening review, sized to the time you've got.
You drill, we schedule
Solve, rate each one, and the misses come back on the right day. Clear the queue and you'll see All Caught Up. Then you're free.
"Can't I just use game review for this?"
Standard game review is great for the one-time autopsy. Here's where you went wrong, retry it now if you like, and then it's gone. Blunders is built for what comes after: the queue that brings that mistake back next week, and the week after, until your accuracy on that pattern is real and permanent.
- One-time report per game
- Retry a mistake right now
- You revisit it only if you remember to
- A persistent queue across every game
- The same mistake scheduled to return until it sticks
- A queue you can filter to only your recurring weaknesses
We're not replacing your analysis. We're the spaced-repetition layer on top of it.
We read your games so your practice is actually yours.
Nightly analysis
Link your account once. Each night we pull your new games and run engine analysis on every one, then flag the moves that cost you material or the game. No uploads, no babysitting.
Consistent engine depth on every game, then the turning points pulled out for you.
Plain-English mistakes
We say what happened in plain words, like "you left a knight hanging," right next to the engine's best line and evaluation. The what and the why, together.
New to chess? No jargon required.
A coach that knows your profile
Ask why a move failed or what to study next. The coach works from a short summary of your real games: your rating, your top recurring weaknesses, the patterns you keep missing, and your current opening focus. A sharp summary, not your whole database.
Calibrated to you, 800 to 2200.
Beginner? We start with the pieces you're hanging and keep the language plain. Stronger player? The queue pulls from puzzles up to roughly 2700 and targets the positional and conversion errors that actually cost you points, not beginner forks you'd never miss. Your queue comes from your own games, so it can't stay too easy or too hard for long.
We turn the queen you just dropped into easy, plain-English practice.
The recurring tactical and opening leaks that keep stalling your rating.
Missed exchanges and sub-pawn endgame slips, the points you actually lose.
Examples. Same loop, tuned to the mistakes in your own games.
You always know your review load, and when you're done.
Due at a glance
A badge shows what's due now, today, and this week, broken out by theme, so a session is never a guess.
You set the pace
Each rating shows what it does: Hard re-tests it tomorrow, Easy spaces it out a couple of weeks. You decide how hard a pattern still feels, and the schedule adapts per card from there.
All caught up
Clear the queue and you get the celebration, plus exactly when your next reviews land. No silent empty screen.
Run the loop. Stop repeating the blunder.
Link your chess account or paste a PGN. We backfill puzzles from games you've already played, so your first queue is ready as soon as analysis finishes.