Try to match relative magnitude of NNUE eval to classical
authormstembera <MissingEmail@email>
Fri, 14 Aug 2020 11:49:33 +0000 (04:49 -0700)
committerJoost VandeVondele <Joost.VandeVondele@gmail.com>
Fri, 14 Aug 2020 14:39:52 +0000 (16:39 +0200)
commit6eb186c97e9d808970d0b1369bcd7aca60612e26
treedd67ac3cf8d3d2974de3a5c34045a7152e1fe79d
parente5f450cf0bfe5a34dd4ea51a5592a71be4514601
Try to match relative magnitude of NNUE eval to classical

The idea is that since we are mixing NNUE and classical evals matching their magnitudes closer allows for better comparisons.

STC https://tests.stockfishchess.org/tests/view/5f35a65411a9b1a1dbf18e2b
LLR: 2.94 (-2.94,2.94) {-0.50,1.50}
Total: 9840 W: 1150 L: 1027 D: 7663
Ptnml(0-2): 49, 772, 3175, 855, 69

LTC https://tests.stockfishchess.org/tests/view/5f35bcbe11a9b1a1dbf18e47
LLR: 2.93 (-2.94,2.94) {0.25,1.75}
Total: 44424 W: 2492 L: 2294 D: 39638
Ptnml(0-2): 42, 2015, 17915, 2183, 57

also corrects the location to clamp the evaluation (non-function on bench).

closes https://github.com/official-stockfish/Stockfish/pull/3003

bench: 3905447
src/evaluate.cpp
src/nnue/evaluate_nnue.cpp