Blunder GymFree during early access
Stop making the same chess mistakes.
Blunder Gym finds the mistakes in your own games, shows you your patterns, and turns them into a few minutes of drills a day.
Every drill is a position from one of your own games.
How it works
Generic puzzles train someone else’s weaknesses. These are yours.
Bring your games
Enter your Lichess or Chess.com username. We pull your last 100 games.
Find your patterns
Stockfish checks every move and tags each mistake: hung pieces, missed tactics, missed mates, time trouble.
Drill daily
5–10 positions a day from your own games. Get one right and it comes back in 3, 7, then 21 days.
Your patterns
See what you actually get wrong
Not “improve your tactics”. Specific things, counted from your own games, that you can fix.
Every week your new games are imported and your patterns update, so you can see them shrink.
Your patterns
Mistakes by type
This month vs last month
- Hung piecedown 40%
- Missed tacticdown 18%
Example data.
Also included
Openings to learn. Games to review.
Opening lessons
60 openings, learned move by move
30 for White and 30 for Black, from beginner to advanced. Learn each main line by playing it, with an arrow and a note for every one of your moves, then play it from memory.
- Four steps: learn, practise, traps & sidelines, master
- Reviews after 1, 3, 7 and 21 days until it sticks
Game analysis
Every move of a game, checked
Pick one of your last 100 games or paste any PGN. Stockfish marks each inaccuracy, mistake and blunder, shows the better move and gives both players an accuracy score.
- Runs in your browser
- Opens straight from any drill
Your coach
A coach that talks you through it.
Hear every move
Hints, answers, lesson notes and game reviews, read aloud. Moves are said as words, like “knight takes d5”. On a computer it’s a natural AI voice that runs on the device itself.
Coach review
One click walks you through a game: your accuracy, then each of your mistakes and blunders explained, and any blunders of your opponent’s that you didn’t punish.
Feels like a game
Wooden move sounds, a chime and confetti when you find the move first time, and a streak that grows each day you train.
Pricing
One plan. Everything included.
Free during early access, then
£6.99 / month
- Your last 100 games analysed
- Personal mistake patterns
- Daily drills from your own games
- 60 opening lessons, with reviews
- Endgame basics: checkmates and pawn endings
- Move-by-move game analysis
- A voice coach, and Coach review
- Weekly progress tracking
Cancel any time before the 5 days are up and you pay nothing.
FAQ
Questions
Do I need to log in to Lichess or Chess.com?
No. Your games are public, so we only need your username.
How are mistakes found?
Stockfish, the strongest free chess engine, checks every move you made. A drop of about a pawn is a mistake, two pawns a blunder. Positions that were already won or lost are skipped.
Where is my data kept?
In your browser, on this device. The analysis runs on your computer, so your games never pass through our servers.
How does the free trial work?
You get everything free for 5 days. You add a card when you start, and you’re charged £6.99 a month (or the same in your own currency) from day 6, unless you cancel before then. Cancel any time in Settings → Manage subscription.
How long does the first analysis take?
About 2–3 minutes for 100 games on a laptop. You can start drilling as soon as the first few games are done.
Does the coach talk?
Yes: hints, answers, lesson notes and game reviews are read aloud, and you can turn it off. On a computer it’s a natural AI voice that runs on your device (a one-time download of about 95 MB); on phones and tablets, your device’s own voice.
Where do the opening lessons come from?
The opening names and first moves come from Lichess’s open database of openings. Every main line and trap is checked with Stockfish before it’s added.
Turn your last 100 games into today’s training.
It takes a username and a couple of minutes.
Analyse my games, freeYour training
Hi,
Your games
Today’s drills
Opening lessons
Game analysis
Pick one of your recent games, or paste any PGN, and Stockfish checks every move.
Move calculator
Find the best move in any position, or train calculating moves ahead in your head.
Your patterns
Mistakes by type
Your openings
What you play, and the openings your games went into (named from Lichess’s openings list)
Your progress
Mistakes per game, week by week
This month vs last month
Settings
This device only has basic voices. For a more natural one, download an English voice marked Premium or Enhanced in its speech settings (on a Mac: System Settings › Accessibility › Spoken Content › System voice › Manage Voices). It’s picked up automatically.
Your data
Everything is saved in this browser. Download a backup to keep it safe or to move it to another device.
Opening lessons
Four steps for each one: learn it with arrows, practise it from memory, its traps and sidelines, then master it.
Endgame basics
Checkmate with a queen, a rook or two rooks, and push a pawn through to a new queen. Learn each one with arrows, then do it yourself against Stockfish.
Move calculator
Game analysis
Stockfish checks every move of a game, right here in your browser.
Your recent games
Pick one to analyse
Paste a game
A PGN from any site or book
The blue arrow is Stockfish’s best move in the position shown. On a keyboard, ← and → step through the game.