Source Authorship Forensics
A source read of jonny-reckless/pawnstar, contrasted with Stockfish.
Pawnstar has been developed by Jonny Reckless since 2014 — a 612-commit, twelve-year personal project, long predating AI code generation. The human pedigree is not in question.
But recently the repo gained an active AI collaborator: 10 commits are authored by Claude <noreply@anthropic.com>, and they do real work — an int8 NNUE quantisation study, an int8 output-layer forward pass (“+31.8 Elo at 8+0.08”, SPRT-verified), and an AWS GPU training launcher. There is a CLAUDE.md. Every AI change is gated by the author’s SPRT testing — AI as an actively-used tool inside a veteran’s rigorous loop, much like Arasan.
Confidence: High — a human veteran project, verifiably AI-assisted.
| # | Signal | What it shows | Weight |
|---|---|---|---|
| 1 | 612 commits over ~12 years (since 2014) by one named author | Deep, long-horizon human authorship | Strong |
| 2 | 10 commits authored by Claude doing real work (int8 NNUE, AWS training) | Actively AI-assisted, and transparently so | Nuance |
| 3 | A CLAUDE.md in the repo | Configured AI-assistant workflow | Nuance |
| 4 | Every AI change SPRT-gated (e.g. “+31.8 Elo at 8+0.08”); header-only design; Go/Rust parity ports | A rigorous human testing loop directing the tool | Strong |
| Where it resembles Stockfish |
|---|
| NNUE (with int8 quantisation) evaluation |
| Lazy SMP parallel search; lockless transposition table |
| SPRT-driven, Elo-measured development |
| High-performance move generation |
| Where it differs |
|---|
| Header-only C++23 design (only main.cpp compiled) |
| One veteran author + AI collaborator vs a global team |
| Its own bit-exact Go and Rust ports |
| No Stockfish code — independent lineage |
Pawnstar is a human-written engine of twelve years’ standing that has taken on an AI collaborator for recent work — with Claude authoring real, SPRT-verified commits under the author’s direction. It lands in the AI-assisted band, at the veteran-led end alongside Arasan: unmistakably a person’s long project, now tool-augmented. Strong Stockfish-technique similarity; none of its code.