FiveZero

A Gomoku (five-in-a-row) engine & desktop game, written in Python.

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The game

Classic Gomoku on a 15×15 board — line up five stones to win. Play human vs engine, human vs human, or drop two engine versions into the AI-vs-AI arena and watch them fight a scored series.

How the engine works

FiveZero picks its move with iterative-deepening alpha-beta minimax under a per-move time budget: it searches depth 1, then 2, then 3… and plays the best move from the deepest search it finished before the clock ran out.

• Evaluation — the position is scored by recognising line patterns (open twos and threes, fours, five-in-a-row…), summed as engine minus opponent. The side to move gets a tempo bonus, since having the initiative is worth something.
• Incremental evaluation — rather than rescanning the whole board at every leaf, the engine keeps a running per-colour score and updates only the few line segments passing through the square just played. Leaf evaluation is therefore O(1).
• Move ordering — candidates are ordered to make alpha-beta prune earlier, which buys extra search depth for free.
• Randomised tie-break — among equally-best moves one is chosen at random, so otherwise-identical games diverge (essential for fairly benchmarking two versions).
• Speed — the hot loops are JIT-compiled to native code with Numba.

Colours: black is 1, white is 2, empty is 0; black always moves first.

Run from source

pip install pygame numba numpy profilehooks
python main.py

Build the macOS app

The bundled script packages everything into a double-clickable .app (and a .zip to send).

chmod +x distribution/build.sh   # once
./distribution/build.sh

It generates the icon, builds with PyInstaller, and drops both files in distribution/:

• Gomoku.app.zip — the file to share
• Gomoku.app — unzipped alongside, for local testing

Notes: macOS only, and the build is architecture-specific — the recipient's Mac must match (uname -m: arm64 = Apple Silicon, x86_64 = Intel). Since the app isn't Apple-signed, the first launch needs a right-click → Open → confirm; after that, double-click works normally.

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_{A personal project. Named after AlphaZero.}