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Jev Chess

Play chess against Jev and inspect the moves it considered.

What Jev decides

Which legal move to play and where the position sits on a seven-level evaluation scale.

Jev Chess pits Jev against people, Stockfish, or OpenRouter models and shows its move probabilities alongside saved games.

CHOICESCORE
Jev role
Choose a legal chess move and evaluate the current position.
Input
The board state, move history, and code-generated descriptions of legal moves.
Output
A Choice over legal moves and a Score for the position.
Decision frequency
On each Jev move.
Fallback
Chess code enforces legal moves and game-ending rules.
Author reported · Source reviewed

How it works

Input
The board state, move history, and code-generated descriptions of legal moves.
Jev
CHOICE + SCORE
Output
A Choice over legal moves and a Score for the position.

Overview

Chess code enumerates legal moves and describes their tactical facts before asking Jev to choose a move and score the position in one request. The app displays likely moves as arrows, records completed games, and can run several model opponents at once. The repository reports game results and move-analysis experiments; these are author-reported, not independent benchmarks.

Language
JavaScript
License
MIT
Author
choxos
Sources checked Sep 26, 2026

Sources

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