Study of the Proper NNUE Dataset
Daniel Tan, Neftali Watkinson Medina
TL;DR
The paper tackles the problem of poorly understood NNUE dataset construction by proposing a replicable pipeline to generate and filter quiet positions. It combines data from 44,000 grandmaster Xiangqi games with 30,000 synthetic self-play games, then uses margins $M_1$ and $M_2$ to prune tactically volatile positions, producing robust training data. A compact NNUE model with $3240$ inputs ($1620$ per side) and a $256$-unit hidden layer demonstrates substantial strength gains, achieving around $+100$ Elo and a $65\%$ win rate against a handcrafted baseline, with gains preserved when paired with a more complex evaluator. The work argues for a general, replicable dataset-generation approach that can extend to other chess variants and evaluation functions, potentially guiding future NNUE training pipelines.
Abstract
NNUE (Efficiently Updatable Neural Networks) has revolutionized chess engine development, with nearly all top engines adopting NNUE models to maintain competitive performance. A key challenge in NNUE training is the creation of high-quality datasets, particularly in complex domains like chess, where tactical and strategic evaluations are essential. However, methods for constructing effective datasets remain poorly understood and under-documented. In this paper, we propose an algorithm for generating and filtering datasets composed of "quiet" positions that are stable and free from tactical volatility. Our approach provides a clear methodology for dataset creation, which can be replicated and generalized across various evaluation functions. Testing demonstrates significant improvements in engine performance, confirming the effectiveness of our method.
