Make new nmp params tunable

bench 6356992
sroelants · Oct 6, 2024 · a3b7ae8 · a3b7ae8
1 parent fc9122c
commit a3b7ae8
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Showing 2 changed files with 9 additions and 1 deletion.
diff --git a/simbelmyne/src/search/negamax.rs b/simbelmyne/src/search/negamax.rs
@@ -239,7 +239,9 @@ impl<'a> SearchRunner<'a> {
         // shouldn't bother searching it any further
         //
         ////////////////////////////////////////////////////////////////////////
-        let nmp_margin = -120 + 20 * depth as Score + nmp_improving_margin() * improving as Score;
+        let nmp_margin = nmp_base_margin() 
+            + nmp_margin_factor() * depth as Score 
+            + nmp_improving_margin() * improving as Score;
 
         let should_null_prune = try_null
             && !PV

diff --git a/simbelmyne/src/search/params.rs b/simbelmyne/src/search/params.rs
@@ -50,6 +50,12 @@ pub mod tunable_params {
     #[uci(min = 0, max = 8, step = 1)]
     const NMP_REDUCTION_FACTOR: usize = 4;
 
+    #[uci(min = 0, max = 100, step = 5)]
+    const NMP_BASE_MARGIN: i32 = -120;
+
+    #[uci(min = -200 , max = 0, step = 10)]
+    const NMP_MARGIN_FACTOR: i32 = 20;
+
     #[uci(min = 0, max = 150, step = 10)]
     const NMP_IMPROVING_MARGIN: i32 = 70;