deepcrayon
/
stockfish
1
0
Fork 0
Code Releases Activity

Simplify Reduction Formula 

Formula now only contains one coefficient. Making it much easier to tune.

STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 187443 W: 34858 L: 35028 D: 117557

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 88329 W: 11982 L: 11953 D: 64394

Bench: 7521394

Resolves #591
pull/592/merge
VoyagerOne 2016-02-28 13:28:22 +00:00 committed by Joona Kiiski
parent d5ba8e827d
commit 45a309d92e
1 changed files with 15 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
src/search.cpp
View File

@ -179,22 +179,23 @@ namespace {
void Search::init() {
const double K[][2] = {{ 0.799, 2.281 }, { 0.484, 3.023 }};
const bool PV=true;
for (int pv = 0; pv <= 1; ++pv)
for (int imp = 0; imp <= 1; ++imp)
for (int d = 1; d < 64; ++d)
for (int mc = 1; mc < 64; ++mc)
{
double r = K[pv][0] + log(d) * log(mc) / K[pv][1];
for (int imp = 0; imp <= 1; ++imp)
for (int d = 1; d < 64; ++d)
for (int mc = 1; mc < 64; ++mc)
{
double r = log(d) * log(mc) / 2;
if (r < 0.80)
continue;
if (r >= 1.5)
Reductions[pv][imp][d][mc] = int(r) * ONE_PLY;
// Increase reduction when eval is not improving
if (!pv && !imp && Reductions[pv][imp][d][mc] >= 2 * ONE_PLY)
Reductions[pv][imp][d][mc] += ONE_PLY;
}
Reductions[!PV][imp][d][mc] = int(std::round(r)) * ONE_PLY;
Reductions[PV][imp][d][mc] = std::max(Reductions[!PV][imp][d][mc] - ONE_PLY, DEPTH_ZERO);
// Increase reduction for non-PV nodes when eval is not improving
if (!imp && Reductions[!PV][imp][d][mc] >= 2 * ONE_PLY)
Reductions[!PV][imp][d][mc] += ONE_PLY;
}
for (int d = 0; d < 16; ++d)
{