Changelog

Last updated 21 July 2026

User-visible changes, newest first. Bugs or requests: feedback@openbookchess.com.

Game review 21 July 2026

New repertoire check: fetch your recent Lichess and Chess.com games and see where each one left your prep — prepared moves you mixed up, and opponent replies you hadn't covered.
Repeat offenders group together and rise to the top; click a result to jump to the position and fix it.
Standard chess only, bullet optional, up to 100 games per site. Runs entirely in your browser — your games and usernames never touch our servers, and it works for guests.

You can now save up to 40,000 positions (20,000 for each color) — four times the old limit.

New repertoire check: Stockfish scans your prepared moves and flags ones that lose ground, ranked by how often you'd face the position. Runs in your browser.
Click a result to jump to the position and fix it.

Save part of your repertoire — your anti-Sicilian lines, say — as a named set and practice just those lines.
Sets are anchored to a position, so new lines through it join automatically.
Practicing a set early doesn't inflate your review intervals; misses still count.

Fixed the opening database disappearing in landscape on phones, plus layout on short screens and hover states on touch devices.

Move rows show a popularity bar alongside win/draw/loss (user request).
Masters picks (★) and engine picks (◆) use distinct shapes, with tooltips (user request).
Cleaner board arrows and better board centering on phones.
Fixed: replaying a line with the keyboard offers "add to repertoire" again (user report).

Repertoire edits are instant, and likely next positions are prefetched.
The eval bar now shows in both Build and Practice.
Practice starts with the color you've practiced least recently, instead of always White.

Stockfish runs in your browser: eval bar and best-move markers in Build mode (user request).
PGN import and export, so you can bring an existing repertoire or take yours elsewhere (user request).
The Practice tab shows how many lines are due.

A position can hold more than one prepared move; practice drills each branch as its own line.
Redesigned mobile controls under the board.

Tutorial for new users, a rating prompt, account deletion, and the privacy policy and terms pages.

New repertoire check: find popular opponent moves you have no answer to, ranked by how likely you are to face them.
Rating setting — the opening database shows games from players near your level.
Deleted lines go to a restorable trash. Visual redesign.

Lichess sign-in, opening-data caching, and ★ markers for master-approved moves, in preparation for public release.

Built as the developer's personal opening trainer: a board, the Lichess opening database, and spaced-repetition practice.