Source Authorship Forensics

Gyatso — human-written, or AI-generated?

A source-level read of GyatsoYT/GyatsoChess, contrasted with Stockfish.

Author GyatsoYTLanguage NimScope ~25 Nim files · 34 commitsStrength CCRL 2095 → ~3300Analyzed 2026-07-10Stockfish similarity Moderate →
Verdict · Human-Written

A human engine in Nim, improving fast and expertly.

Gyatso is written in Nim — a rare language for a chess engine and a distinctly human choice — and its commit log reads like a competitive engine dev’s changelog: “TT Three-Entry Clustering”, “Improved IIR (Also Trigger on Stale TT Entry)”, “wasPV Flag Tracking”, “Prevent Consecutive Null Moves in NMP”. CCRL ratings climb version over version (2095 → 2555 → ~3300).

No AI residue. Each commit is a specific, well-understood search improvement — the signature of a person who knows the craft.

Confidence: High — expert, incremental, human development.

Part of a series applying the same lens to chess-engine repositories — from the AI-pasted Luna and agent-built Owen, through the AI-assisted Triumviratus, to a range of human-written engines.  See the full index →

1Evidence

Expert search-improvement commits, in an unusual language, with measured Elo gains.

#SignalWhat it showsWeight
1Written in Nim — a rare, deliberate language choiceNot a generator default; a person’s pickDecisive
2Commits are specific search improvements (TT clustering, IIR, wasPV, NMP guards, LMR history fixes)Deep, one-idea-at-a-time engine expertiseStrong
3CCRL ratings tracked and climbing across versionsA real, measured development loopStrong
4Zero AI residue or agent artifactsNo generated-code fingerprintsSupport

2Compare & contrast with Stockfish

Where it resembles Stockfish
Transposition table with three-entry clustering
Modern search: NMP, LMR, IIR, PV tracking
Incremental, individually-motivated improvements
Version-over-version strength measurement
Where it differs
Written in Nim vs C++
One author vs a global team
Younger, smaller codebase
Mid-to-strong hobby engine scale

Bottom line

Gyatso is a human-written engine — an expertly-developed Nim project whose commit history is a catalogue of specific, well-understood search improvements with measured Elo gains. Language choice and engineering depth alike mark it as a person’s work.