Game analysis and tactical diagnosis · No account needed
Find the tactics you missed and the threats you allowed in your Chess.com or Lichess games. Review the real positions, then learn and practice the patterns.
Import recent games with your username and review the tactics you missed or allowed.
Open the position, replay the engine line, and try other candidates on the board.
Move on to related guides and corrective practice. With an account, your training progress and review schedule are saved.
Start with a username, or paste a PGN into game analysis. The engine runs in your browser.
Review recent rated games in the time control you choose. See missed tactics and allowed threats as counts and positions. A small sample doesn't establish your skill or weaknesses.
Diagnose my gamesStart with a Chess.com or Lichess username, a PGN, or a Lichess game URL. Compare move evaluations and engine candidates, then try alternatives on the board.
Analyze a gameKnowing a tactic's name doesn't mean you'll see it as a candidate in a game. Besides puzzles, you can practice a fixed order for scanning the board before you choose a move.
Solve puzzles from an open database across 53 tactics. Accuracy and level are tracked separately for each tactic, and SM-2 review dates decide which one comes next.
Try this drillBefore you look for the answer, list every check, then every capture, then play your best move. The candidate list comes from the legal moves, so you see exactly which ones you missed.
Try this drillFind pieces that are undefended, or that can be captured with no legal recapture. You select squares rather than play moves. Kings and pawns are excluded, and some positions have no matching pieces.
Try this drillSolve it now, no login needed. The puzzle changes daily.
Study pins, forks, skewers, and mating patterns with explanations, diagrams, and playable examples. Some guides also include examples from real games, and none require signing in.
One piece attacks two or more enemy pieces at once
Moving a piece would expose its king or another valuable piece behind it
Attack a high-value piece to hit the piece behind it (a pin in reverse)
Move a piece to reveal an attack from the piece behind
Give up material for a greater advantage
Checkmate on the 1st/8th rank. The most-tagged named mate pattern in this site's puzzle set
Checkmate in two moves. Train 2-move calculation
A knight mates a king hemmed in by its own pieces
Each of the 53 tactics has its own level. Fork, pin, discovered attack and the rest each track a level (1-5), an XP bar, and accuracy.
When you're signed in, your results set a review date for each motif. Due reviews come first, and extra practice on the same day doesn't stretch the interval.
Motifs where your accuracy or training level is low come up more often. To look for weaknesses in your actual games, use game analysis alongside your puzzle results.
See your strengths and gaps at a glance. A radar chart plots six skill axes: Basic, Attacks, Defense, Mates, Calculation, and Special Moves.
Stockfish 18 runs right in your browser. Paste a PGN or a Lichess game URL to find the tactics you missed. No install, login, or subscription needed.
Learn before you train. 53 tactics have in-depth guides with explanations and verified example positions, and most include interactive game replays.
A tactic is a concrete move or sequence that exploits the position to gain an advantage or avoid a loss. Common patterns include forks, pins, and skewers. Some tactics win material or force mate; others save a difficult position.
Yes. If you know the rules, start with the introductory guides and puzzles. The four stages suggest a learning order, and you can revisit a concept whenever you need to.
Review timing is tracked per concept, such as pin or fork, rather than per puzzle. When a concept is due, the trainer first tries to choose a position you haven't attempted recently. A puzzle may repeat if too few alternatives are available.
Yes. Daily training, 53 in-depth guides, and Stockfish analysis in your browser are all free. There is no paid plan right now.
It covers fundamentals like forks, pins, skewers, and discovered attacks, mating patterns such as back-rank, smothered, and Arabian mate, and special rules like en passant and promotion. 53 tactics currently have in-depth guides with definitions and verified diagrams, and most include examples from real games.
Analysis and diagnosis work without signing in.