Further push the LMR pedal

zamar · mcostalba · commit 8e269d781af1 · 2010-05-05T12:20:39.000+01:00
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 &lt;mcostalba@gmail.com&gt;
diff --git 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);
       }

Original file line number	Diff line number	Diff line change
`@@ -549,8 +549,8 @@ void init_search() {`
`549`	`549`	`for (int i = 1; i < 64; i++) // i == depth (OnePly = 1)`
`550`	`550`	`for (int j = 1; j < 64; j++) // j == moveNumber`
`551`	`551`	`{`
`552`		`- double pvRed = 0.5 + log(double(i)) * log(double(j)) / 6.0;`
`553`		`- double nonPVRed = 0.5 + log(double(i)) * log(double(j)) / 3.0;`
	`552`	`+ double pvRed = log(double(i)) * log(double(j)) / 3.0;`
	`553`	`+ double nonPVRed = log(double(i)) * log(double(j)) / 1.5;`
`554`	`554`	`PVReductionMatrix[i][j] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(OnePly)) : 0);`
`555`	`555`	`NonPVReductionMatrix[i][j] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(OnePly)) : 0);`
`556`	`556`	`}`