About Opening Puzzles
Who makes Opening Puzzles
My name is Thijs Terlouw. I live in the Netherlands and play club chess, with a Dutch national rating of about 1700–1800.
I started Opening Puzzles for two reasons. The first is my own chess: like most club players, I lose more games to an opening trick I should have known than to deep strategy, and I wanted a way to train exactly those moments. The second is my kids. They are learning chess, and I wanted something better for them than memorising move orders: short positions from real games where you spot the mistake and learn how to punish it. Everything on this site, from the studies to the trap pages and the puzzles, is something I use myself or with them.
Opening Puzzles is a personal project that I build and maintain myself. New puzzles are added every month from fresh Lichess games, and every study and trap page is checked move by move with Stockfish before it goes online. I write the texts with the help of AI tools and check every line with Stockfish. If something looks wrong, or there is an opening you would like to see covered, I would love to hear from you.
What the puzzles are
Most chess puzzle collections start from the middlegame. Opening Puzzles starts earlier: every puzzle is a position from the first moves of a real game where one side has just made a mistake, and your job is to find the move that punishes it. The goal is to recognise those traps in your own openings before you meet them over the board — and to know how to cash in when your opponent walks into one.
Where the puzzles come from
The source is the public Lichess open database, which publishes every rated game played on Lichess. Each month we scan the new games for moments early in the opening where the position was roughly level — within a pawn — and one move later the other side is clearly winning. Only games where both players are rated 1800 or higher and the time control is at least three minutes are used, so these are mistakes that strong club players actually make, not bullet blunders.
How every puzzle is checked
A candidate position only becomes a puzzle after Stockfish confirms it at depth 20. The punishing move must leave its side at least a pawn and a half ahead, it must be better than every alternative by the same margin — so there is exactly one answer — and the win must still hold at the end of the solution line, at most seven half-moves later. Positions with several equally good solutions, or with only a small edge, are thrown out. Each puzzle is then tagged with its opening (ECO code and variation name) and given a difficulty: longer solutions, quiet first moves and smaller advantages make a puzzle harder; winning a queen's worth of material or forcing mate makes it easier.
How to use the site
- Learn — interactive studies that walk through an opening's ideas, main variations and the mistakes players make at different rating levels.
- Traps — the famous opening traps, each on its own page: the losing move, the punishment, how often it happens at each rating and the move to play instead.
- Train by opening — puzzles from one opening family or one specific variation, as White or as Black.
- Explore — play the first moves of your repertoire on a board to find its name and the puzzles that go with it.
Your progress and daily streak are stored only in your own browser; there are no accounts. The site is free and supported by advertising.
Credits
Game data from the Lichess open database (CC0). Engine analysis by Stockfish (GPL). Pieces: the cburnett set from lichess-org/lila (CC BY-SA 3.0). Opening names follow the Lichess chess-openings list. Opening Puzzles is an independent project and is not affiliated with Lichess.
Questions, corrections or a puzzle that looks wrong? Get in touch.