Knight Shift

Blunderbuss · chess training from your own games

Stop making the same blunder twice.

Blunderbuss finds the blunders in your own chess.com, Lichess and over-the-board games, then drills you on each one until the right move comes without thinking.

How it works

  1. 1

    Bring in your games

    Type your chess.com and Lichess names, or drop in a PGN of your tournament games. Every game comes in, blitz and bullet too.

  2. 2

    Stockfish finds your blunders

    Your rapid and classical games are checked move by move. Every moment where one move threw the game away becomes a drill.

  3. 3

    Drill until it sticks

    Find the move you missed. Get it right and it comes back in a day, then three, then a week. Miss it and it's back in 90 minutes.

Why Blunderbuss works

Positions you remember

No random puzzles. Every drill is a position from a game you played, with your opponent, the date and the event, so you remember the game, and the lesson sticks.

Explained on the board

Miss one and a lesson plays the idea out move by move, with arrows: the threat, the best line, and what your move allowed.

Right at your level

A drill rating follows how you're doing, and new drills are picked close to it: hard enough to teach you something, easy enough to keep you going.

Built like a game

Streaks, sounds, confetti and a background that ripples with every move. Turn any of it off in settings.

From Blunder to Mastered

Each drill climbs four stages as you get it right, and drops back to Blunder when you miss it.

  1. Blunderback in 90 minutes
  2. Noviceback tomorrow
  3. Juniorback in 3 days
  4. Masteredback in a week, then two

Play in your look

Three looks, each with its own board, type and moving background. Try one:

Your next blunder is already in your games.

Find it before your opponent does.

Create a free account

Free to start: drill your 20 most recent blunders.