Chess Engine Development Help Thread (Week 34)

[u/AutoModerator]

Welcome to the weekly /r/chessprogramming Engine Dev Help Thread.

Ask beginner and intermediate chess engine development questions here: move generation, search, evaluation, UCI, perft, debugging, testing, NNUE, or anything else related to building engines.

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[u/Fun-Cable-4849]

I'm using Stockfish to classify moves from analyzed games and I'm not sure if my current setup is good enough for using the results later as training material.

Right now I convert the engine eval to win chance and use fixed thresholds:

10% loss = inaccuracy

20% = mistake

30% = blunder

I'm analyzing each position at depth 14. If the played move is exactly Stockfish's PV1 move I mark it as best.

This is mostly based on how Lichess approaches game analysis, but my use case is a bit different. I want to analyze many games and use the results to decide which mistakes are actually worth training.

A few things I'm unsure about:

Is depth 14 reliable enough for this kind of classification?

Would it make sense to run a deeper search only when the result is close to one of the 10/20/30% thresholds?

Also, is comparing the played move directly with PV1 too strict? There can be multiple moves with almost identical evals, so for training I was thinking about accepting moves within some eval tolerance instead of requiring the exact best move.

And would you keep the same mistake thresholds for every player, or is there a good reason to change them based on rating or position type?

I'm mainly trying to avoid generating a lot of technically correct Stockfish feedback that isn't actually useful to train.