Jev Chess

A 6.5M-parameter independent chess policy model built from Jev's public description: it returns a calibrated distribution over legal moves in one forward pass, with a self-reported held-out top-1 of 36.5%, ECE 0.036 and Elo 1239 plus or minus 51.

A 3D chess game played against TypeSafe Jev, described as realistic and mobile-friendly with Beginner, Pro and Legendary levels, free in the browser. Only the page's metadata could be recovered; the game itself is client-rendered.

A Python benchmark that evaluates LLMs' reasoning and instruction-following by making them play chess against a random player or the Komodo Dragon engine in multi-turn dialogs, separating chess skill from protocol durability.

A public operator lab for TypeSafe Jev: a chess match as the flagship page, a row of smaller judgment booths, and one shared client that keeps the API key out of the browser via a local Python server or a Cloudflare Worker.

Browser chess and Chess960 where code works out every legal move's facts and Jev picks one per turn as a single typed Choice; the mirror of the chriswijnia.com/lab/chess monorepo.

A browser chess coach where Stockfish (WASM) owns the truth about the position and Jev makes the coaching judgment after every move, with templates and a small writing model supplying the words. Status: Wave 0 scaffold and Jev feasibility spike.

An interactive chess experiment on chriswijnia.com: play Jev, TypeSafe's System One model, a simple engine or a friend, or watch Jev play itself. Each turn Jev weighs every legal move at once as one typed Choice and shows how sure it is.

Maxim Saplin ran TypeSafe Jev on LLM Chess by turning each position into one Choice question over the legal moves. jev-latest landed around rank 59 at Elo 242.9, next to qwen3.6-27b and o4-mini-medium, at roughly $0.0015 and 36 seconds per game.

A study of using Jev inside Stockfish search and multi-teacher distillation. A bot with Jev's judgment distilled into a compact evaluator climbs above a 2200 Lichess bullet rating, and averaging Jev with Qwen3-32B labels beats spending the whole labeling budget on Qwen alone by 9.6 Elo.

A live 3D chess match where Jev plays both sides with different personas and exposes the probability split behind every move.