In crazyhouse Fairy-Stockfish is only around 200 Elo weaker (~100 of which due to speed) than the multi-variant Stockfish used on lichess for which we heavily tuned dozens/hundreds of parameters (including piece values) specifically for crazyhouse, so the generic adaptions already seem to work well. However, I have not much doubt that playing strength could be increased a lot for shogi by improving the evaluation, especially since the Stockfish-based engines using evaluation files show that with the same search engine you can get a ~1500 Elo stronger engine, but currently my focus is on adding more features/variants.
Back to the original topic of the thread, I found some more info on the most recent generation of evaluation files for shogi at https://github.com/ynasu87/nnue/blob/ma ... s/nnue.pdf (in Japanese).
Most of the strongest shogi programs nowadays employ a linear evaluation function, which is computationally efficient but lacks nonlinear modeling capability. This report presents a new class of neural-network-based
nonlinear evaluation functions for computer shogi, called NNUE (Efficiently Updatable Neural-Network-based
evaluation functions). NNUE evaluation functions are designed to run efficiently on CPU using various acceleration techniques, including incremental computation. The first shogi program with a NNUE evaluation
function, the end of genesis T.N.K.evolution turbo type D, will be unveiled at the 28th World Computer Shogi