explaingit

emollick/grandmaster

Analysis updated 2026-05-18

1HTMLAudience · generalComplexity · 1/5Setup · easy

TLDR

A single-file HTML chess game where you always win: the rules and move generation are fully real, but the AI opponent is designed to lose every time.

Mindmap

mindmap
  root((Board 7 Chess))
    What it does
      You always win
      Real chess rules
      No install needed
    Features
      Legal move highlights
      PGN export
      Algebraic notation
    Tech
      Single HTML file
      JavaScript only
      No dependencies
    Audience
      Non-chess players
      Casual gamers
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Code map

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filefunction / class

What do people build with it?

USE CASE 1

Play a complete game of chess in your browser without knowing the rules, since legal moves are highlighted and you cannot lose.

USE CASE 2

Export a real PGN game record of your win and share it with chess-playing friends.

USE CASE 3

Study a minimalist single-file JavaScript chess implementation with full legal move generation including en passant and castling.

What is it built with?

HTMLJavaScript

How does it compare?

emollick/grandmasteratypical-chai/motion-graphics-from-css-hyperframescrossrobertj/ninmidi
Stars111
LanguageHTMLHTMLHTML
Setup difficultyeasyhardeasy
Complexity1/53/51/5
Audiencegeneralgeneralgeneral

Figures from each repo's GitHub metadata at analysis time.

How do you get it running?

Difficulty · easy Time to first run · 5min

In plain English

Board 7 is a single-file HTML chess game designed for people who know nothing about chess, built around one simple premise: you cannot lose. You play against a fictional AI opponent called DeepFish 17, which is described as a chess engine with a rating of 4012 and 2.8 million undefeated games. Whatever happens after you make your first move is, as the README puts it, the world's fault. The chess itself is genuine. The game generates all legal moves correctly, including castling, en passant, pawn promotion, and checkmate. The notation panel shows real algebraic chess notation, the kind you would find in a chess book. If you export the game record at the end using the PGN download option, you get an actual game file you could show to a chess player. What is not genuine is DeepFish's competitive spirit. Your legal moves are highlighted so you can pick whichever square looks appealing, and the engine's subsequent play ensures that its own position gradually collapses. The README describes this as a structural guarantee, not encouragement. The entire game is a single HTML file with no external libraries, no build step, and no network connection needed. You open it in a browser and play immediately. The project was built using an AI-assisted development tool called Claude Code. The README notes that the PGN export produces a real game record and suggests showing it to a chess-playing friend, whose observations about Black's collapse will be, as the textbooks say, instructive.

Copy-paste prompts

Prompt 1
I want to add a second mode to the grandmaster chess game where the AI plays a bit more competitively. How is the engine's move selection currently implemented in the HTML file?
Prompt 2
How does the grandmaster chess game generate legal moves for special cases like en passant and castling? Walk me through the relevant JavaScript in the single HTML file.
Prompt 3
I want to change the board color scheme in the grandmaster chess game. Where in the HTML file are the square colors and highlight styles defined?

Frequently asked questions

What is grandmaster?

A single-file HTML chess game where you always win: the rules and move generation are fully real, but the AI opponent is designed to lose every time.

What language is grandmaster written in?

Mainly HTML. The stack also includes HTML, JavaScript.

How hard is grandmaster to set up?

Setup difficulty is rated easy, with roughly 5min to a first successful run.

Who is grandmaster for?

Mainly general.

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