kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-06-28 00:19:50 +00:00
Code Issues Releases Wiki Activity

Simplify the use of classical eval

Browse source 
no benefit of the fallback term (exercised rarely).
Cleanup the associated code.

passed STC
https://tests.stockfishchess.org/tests/view/62f62c2b6f0a08af9f776367
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 67832 W: 18334 L: 18148 D: 31350
Ptnml(0-2): 369, 7171, 18609, 7439, 328

passed LTC
https://tests.stockfishchess.org/tests/view/62f68beb6f0a08af9f77710e
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 104664 W: 28363 L: 28233 D: 48068
Ptnml(0-2): 169, 10162, 31511, 10350, 140

closes https://github.com/official-stockfish/Stockfish/pull/4132

Bench: 6079565
This commit is contained in:
Joost VandeVondele 2022-08-12 12:31:49 +02:00
parent 5f290352cd
commit 15ac117ac4
1 changed files with 18 additions and 23 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

41
src/evaluate.cpp
View file

@ -1053,34 +1053,29 @@ Value Eval::evaluate(const Position& pos, int* complexity) {
Value v;
Color stm = pos.side_to_move();
Value psq = pos.psq_eg_stm();
// Deciding between classical and NNUE eval (~10 Elo): for high PSQ imbalance we use classical,
// but we switch to NNUE during long shuffling or with high material on the board.
bool useClassical = (pos.count<ALL_PIECES>() > 7)
&& abs(psq) * 5 > (856 + pos.non_pawn_material() / 64) * (10 + pos.rule50_count());
// Deciding between classical and NNUE eval (~10 Elo): for high PSQ imbalance we use classical,
// Deciding between classical and NNUE eval: for high PSQ imbalance we use classical,
// but we switch to NNUE during long shuffling or with high material on the board.
if (!useNNUE || useClassical)
{
bool useClassical = !useNNUE ||
((pos.count<ALL_PIECES>() > 7)
&& abs(psq) * 5 > (856 + pos.non_pawn_material() / 64) * (10 + pos.rule50_count()));
if (useClassical)
v = Evaluation<NO_TRACE>(pos).value();
useClassical = abs(v) >= 297;
}
// If result of a classical evaluation is much lower than threshold fall back to NNUE
if (useNNUE && !useClassical)
else
{
int nnueComplexity;
int scale = 1064 + 106 * pos.non_pawn_material() / 5120;
Value optimism = pos.this_thread()->optimism[stm];
int nnueComplexity;
int scale = 1064 + 106 * pos.non_pawn_material() / 5120;
Value optimism = pos.this_thread()->optimism[stm];
Value nnue = NNUE::evaluate(pos, true, &nnueComplexity);
// Blend nnue complexity with (semi)classical complexity
nnueComplexity = (104 * nnueComplexity + 131 * abs(nnue - psq)) / 256;
if (complexity) // Return hybrid NNUE complexity to caller
*complexity = nnueComplexity;
Value nnue = NNUE::evaluate(pos, true, &nnueComplexity);
// Blend nnue complexity with (semi)classical complexity
nnueComplexity = (104 * nnueComplexity + 131 * abs(nnue - psq)) / 256;
if (complexity) // Return hybrid NNUE complexity to caller
*complexity = nnueComplexity;
optimism = optimism * (269 + nnueComplexity) / 256;
v = (nnue * scale + optimism * (scale - 754)) / 1024;
optimism = optimism * (269 + nnueComplexity) / 256;
v = (nnue * scale + optimism * (scale - 754)) / 1024;
}
// Damp down the evaluation linearly when shuffling
@ -1091,7 +1086,7 @@ Value Eval::evaluate(const Position& pos, int* complexity) {
// When not using NNUE, return classical complexity to caller
if (complexity && (!useNNUE || useClassical))
*complexity = abs(v - psq);
*complexity = abs(v - psq);
return v;
}