Further push the LMR pedal

More aggressive LMR reductions.

Tested at different time controls:

- Tested with 1CPU 1+0, after 3000 games, result was +12 ELO

- Tested this with 4CPU 1+0 and got sth around 5-10 ELO increase

- Last one at long time control,after ~1000 games with 10+0 result is:

Orig - Mod: 491 - 520 (+10 elo)

A testing marathon by Joona for this important change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

diff --git a/src/search.cpp b/src/search.cpp
index 17e54e4cd3cbedc32a9656f314fa8ac1514790f2..ed7d6a3499e1838b025fb43b0328ee561bb93edc 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -549,8 +549,8 @@ void init_search() {
   for (int i = 1; i < 64; i++) // i == depth (OnePly = 1)
       for (int j = 1; j < 64; j++) // j == moveNumber
       {
-          double    pvRed = 0.5 + log(double(i)) * log(double(j)) / 6.0;
-          double nonPVRed = 0.5 + log(double(i)) * log(double(j)) / 3.0;
+          double    pvRed = log(double(i)) * log(double(j)) / 3.0;
+          double nonPVRed = log(double(i)) * log(double(j)) / 1.5;
           PVReductionMatrix[i][j]    = (int8_t) (   pvRed >= 1.0 ? floor(   pvRed * int(OnePly)) : 0);
           NonPVReductionMatrix[i][j] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(OnePly)) : 0);
       }