How we make this site

Opening lines and boards

Each opening guide follows a model line. Its first moves are the ones that name the opening in the books, and the engine extends the line to sixteen moves for each side; the counter-palace horse's guide walks through the archive's most played line of that defence instead. The guide explains the line, the main variations and the plans for both sides, and a statement taken from a book, a rulebook or a reference work carries a numbered reference to the list at the end of the page.

The boards of an opening guide are not drawn by hand. The site's code plays each line move by move and draws the position after every move, so a board always matches the moves beside it, and the site's tests replay every model line to check that each move is legal.

The engine

The engine is Pikafish, an open-source xiangqi engine, which the site builds from the engine's published code; the build it runs today is dev-20260923-b562d6ae. When a member asks for an analysis, the engine searches each position of the game until it reaches depth 14 or 400 milliseconds have passed, whichever comes first, and the paid plans give it two or four times as long.

The engine evaluates every move of the model lines and of the line drills in the Learn section, and a move that loses more than 180 centipawns, the engine's unit of advantage, is flagged for review. A puzzle in the Campaign, Rated practice or Puzzle Storm is added only when the engine has proved its mate in the stated number of moves.

The archive and its figures

The archive holds 32,204 games. Each one is replayed through the site's rules engine before it enters the archive, and a game with an illegal move is left out. The figures on the guides and profiles count the 29,164 games between human players; the 3,040 games played by engines are left out of them.

A game belongs to an opening by its first moves, and to a period only when its record carries a year. A score counts a win as one point and a draw as half a point. A best score needs a minimum number of games, at least 30 and more for the most played openings, so that a handful of games cannot top a list.

A program reads the archive's games and writes every figure into one file of the site, and the text, the tables and the boards all read from that file. When the figures change, they are recomputed from the archive and compared with the published ones before the change goes live.

Four languages

Every page has an English, a Vietnamese and a Simplified Chinese edition. The Vietnamese and Simplified Chinese editions are checked against fixed rules for terminology and notation, so the pieces, the openings and the profiled players have the same names on every page of an edition. The Traditional Chinese edition is converted from the Simplified Chinese edition and then adjusted to a fixed list of Traditional Chinese usage rules. Players without a profile and the events keep the Simplified Chinese names the archive records, in both Chinese editions.

The move names in the walkthroughs, the replays and the numbered lines come from the site's code, which writes each move in the reader's notation from the move itself, so the same move reads C2=5 in English, Pháo 2 bình 5 in Vietnamese and 炮二平五 in Chinese. Before a change is published, a check confirms that every edition has a version of every text in the English one.

Review before publication

Every change to a public page is reviewed before it is published. The pages carry the name of the site's editorial team, and this page describes how the team works.

Corrections and dates

If you find a mistake, please tell us through the contact page. We correct it in every language at once. The date under a guide or a profile changes when its content changes, for example a corrected line or a new section, and a typo fix does not change it. New features and new sections are listed on the updates page with the day they went live.

References

The books, rulebooks and records that a page cites are listed at its end, with a link where they are online. They support the facts on the page; the explanations, the boards, the engine checks and the archive figures are the site's own work.