Source Authorship Forensics
A source-level read of ranzuh/ratsu, contrasted with Stockfish.
Ratsu has been developed by one named author across 114 commits over some sixteen months, with CCRL-measured progress recorded version by version. The commits are classic solo engine-dev increments — “Add reverse futility pruning”, “Reduce more in LMR”, “fix ply crash” — the honest, incremental rhythm of a person learning and improving an engine.
No AI residue. A compact, readable, hand-built Rust engine.
Confidence: High — a long-running, incrementally-developed personal project.
Long, incremental, CCRL-tracked personal development.
| # | Signal | What it shows | Weight |
|---|---|---|---|
| 1 | 114 commits over ~16 months by one named author | Sustained solo development, not a one-shot dump | Decisive |
| 2 | Feature-by-feature increments (RFP, LMR/NMP tuning, crash fixes) with CCRL ratings tracked | A genuine learn-and-improve loop | Strong |
| 3 | Compact ~3,600-line hand-written Rust codebase | Readable, personal-scale engineering | Support |
| 4 | Zero AI residue or agent artifacts | No generated-code fingerprints | Support |
| Where it resembles Stockfish |
|---|
| Alpha-beta search with LMR, NMP, futility/reverse-futility pruning |
| Standard move-ordering heritage |
| Versioned, CCRL-tested releases |
| Incremental, one-idea-at-a-time development |
| Where it differs |
|---|
| Rust vs C++; ~3.6k LoC and one author |
| 0x88 board representation rather than pure bitboards |
| Mid-strength hobby engine vs a title contender |
| Younger, smaller codebase |
Ratsu is a human-written engine — a compact, honestly-incremental Rust project by one developer, its progress tracked release by release on CCRL. A textbook example of a personal engine grown the human way.