Pygin
Description
Pygin - a from-scratch UCI chess engine in Python + C, with a hand-written search and evaluation and the entire per-node search loop in C. Built with the help of Claude Code.
Installation
This entry records only its repository, not the path inside it, so there is no
exact command to give. Open the source below and copy the folder into
~/.claude/skills/, or the file into ~/.claude/agents/.
README
Pygin
**A from-scratch chess engine in Python + C.** The search is hand-written.
Since v58 the evaluation is an HCE/NNUE hybrid: the neural net scores positions
inside the main search, and the hand-crafted eval keeps quiescence. There is no
external engine, and the net learned from Pygin's own self-play games only, with
no borrowed data and no borrowed weights.
[`python-chess`](https://pypi.org/project/chess/) is used *only* for board
representation, move generation and legality.
     · Built with **[Claude Code](https://claude.com/claude-code)**
At a glance
| ~2868 Elo | SF-18 UCI_Elo scale | 3.3M nps | the net costs ~30% of it |
| ~+338 Elo | A/B-confirmed, v31→v60 | ~18 ply | from startpos in 5 s |
| +19.11 Elo | v58 NNUE, TIMED | 1.43x | single-thread vs v31 |
| v53+v54 eval lane | +37.52 & +31.20, the two biggest | 1 dependency | python-chess only |
 |
 |
Both charts are self-play. Every C-era version (v31 and up) is A/B-tested against the one before it, and the gains stack to about +338 Elo. Single-thread speed peaked at 1.79× and sits at 1.43× today: v58 hands about 30% of it to the net and still comes out +19.11 ahead. The v30→v31 C rewrite (~34× faster) is off the left edge, so v31 is the honest zero.
The odds lad
Related Skills
Auto Update
Pull the latest ECC repo changes and reinstall the current managed targets.
Ecc Guide
Navigate ECC's current agents, skills, commands, hooks, install profiles, and docs from the live repository su
Epic Claim
Claim an epic issue, stamp coordination state, and sync local ownership.
Epic Publish
Publish a validated epic update back to the issue and local cache.
Epic Review
Mark epic review requested, approved, or changes requested.
Epic Unblock
Sweep blocked epic issues and reopen anything whose dependencies are closed.