---
license: mit
tags:
- chess
- stockfish-19
- soft-labels
- multipv
- piece-count
pretty_name: Local soft positions
---

# Local soft positions

Local **Stockfish 19** MultiPV harvest. Unique boards, piece-count tracked,
1–8 soft policy targets plus White-absolute values.

**300,046** rows. Source id `4`. Vocab `compact` (1968).

## Sampling

Full SF19 vs SF19 games from Lichess ECO starts
(7,852 unique). A row is kept only when its
`n_pieces` is still under a truncated **N(17, 6)** over n ∈ {2…32}.
Deduped by 4-field board key (board, side, castling, ep).

Piece-count in this upload: n=300,046 mean=16.88
std=6.0 peak=15.

`split=1` is a ~5% holdout. Honor `split`.

## Teacher

- Stockfish 19 (`edb0d9db`), EvalFile `nn-1a298aa575a0.nnue`
- Full strength, `Threads=1`, `Hash=64`
- Label: **100,000 nodes / MultiPV=8** / `tau=120`

## Targets

- `n_pieces` — pieces on the board
- `n_soft` — how many of the 8 slots are live (1–8)
- `soft_indices` / `soft_probs` / `soft_cps` / `soft_mates` — STM policy + per-move values
- `cp` / `mate` / `wdl` — **White-absolute** value
- Softmax is `tau=120` over the last complete MultiPV iteration
- Unsearched legal moves are absent, not proven bad

n_soft hist (slots 1–8): [9351, 9167, 8644, 7766, 8304, 19591, 64661, 172562]

## Files

- `data/shard_XXXXXX.parquet`
- `teacher.json`, `openings.json`, `manifest.json`, `stats.json`, `summary.json`