From a65397692a7d1bc1c3e07977481036f642872e1e Mon Sep 17 00:00:00 2001
From: Bruno Dutra <brunocodutra@gmail.com>
Date: Fri, 23 Aug 2024 14:38:52 +0200
Subject: [PATCH] reduce Value range to +-4000

---
 lib/nnue.rs                 |  2 +-
 lib/nnue/material.rs        |  2 +-
 lib/nnue/positional.rs      |  2 +-
 lib/nnue/value.rs           |  2 +-
 lib/search/engine.rs        | 12 ++++++------
 lib/search/ply.rs           |  2 +-
 lib/search/score.rs         |  4 ++--
 lib/search/transposition.rs |  4 ++--
 8 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/lib/nnue.rs b/lib/nnue.rs
index 576c08ba..91ce961d 100644
--- a/lib/nnue.rs
+++ b/lib/nnue.rs
@@ -103,7 +103,7 @@ mod tests {
             for weights in features.array_chunks_mut::<768>() {
                 let (small, _, _) = weights.select_nth_unstable(32);
                 assert!(small.iter().fold(bias, |s, &v| s + v).abs() <= i16::MAX as i32);
-                let (_, _, large) = weights.select_nth_unstable(Positional::LEN - 33);
+                let (_, _, large) = weights.select_nth_unstable(735);
                 assert!(large.iter().fold(bias, |s, &v| s + v).abs() <= i16::MAX as i32);
             }
         });
diff --git a/lib/nnue/material.rs b/lib/nnue/material.rs
index 5b06eecc..111ad2a9 100644
--- a/lib/nnue/material.rs
+++ b/lib/nnue/material.rs
@@ -44,7 +44,7 @@ impl Accumulator for Material {
 
     #[inline(always)]
     fn evaluate(&self, turn: Color, phase: usize) -> i32 {
-        (self.0[turn as usize][phase] - self.0[turn.flip() as usize][phase]) / 32
+        (self.0[turn as usize][phase] - self.0[turn.flip() as usize][phase]) / 80
     }
 }
 
diff --git a/lib/nnue/positional.rs b/lib/nnue/positional.rs
index 5ab0c108..60f5c1a7 100644
--- a/lib/nnue/positional.rs
+++ b/lib/nnue/positional.rs
@@ -44,7 +44,7 @@ impl Accumulator for Positional {
 
     #[inline(always)]
     fn evaluate(&self, turn: Color, phase: usize) -> i32 {
-        Nnue::hidden(phase).forward([&self.0[turn as usize], &self.0[turn.flip() as usize]]) / 16
+        Nnue::hidden(phase).forward([&self.0[turn as usize], &self.0[turn.flip() as usize]]) / 40
     }
 }
 
diff --git a/lib/nnue/value.rs b/lib/nnue/value.rs
index b1718fc3..e63e558b 100644
--- a/lib/nnue/value.rs
+++ b/lib/nnue/value.rs
@@ -9,7 +9,7 @@ pub struct ValueRepr(#[cfg_attr(test, strategy(Self::MIN..=Self::MAX))] <Self as
 unsafe impl Integer for ValueRepr {
     type Repr = i16;
     const MIN: Self::Repr = -Self::MAX;
-    const MAX: Self::Repr = 8000;
+    const MAX: Self::Repr = 4000;
 }
 
 /// A position's static evaluation.
diff --git a/lib/search/engine.rs b/lib/search/engine.rs
index 647ab421..3b00dfac 100644
--- a/lib/search/engine.rs
+++ b/lib/search/engine.rs
@@ -103,11 +103,11 @@ impl Engine {
         depth: Depth,
         ply: Ply,
     ) -> Option<Depth> {
-        let bounds = -(alpha - 60)..-(alpha - 401);
+        let bounds = -(alpha - 24)..-(alpha - 161);
         let r = match (alpha + next.clone().see(m.whither(), bounds)).get() {
-            ..=60 => return None,
-            61..=200 => 1,
-            201..=400 => 2,
+            ..=24 => return None,
+            25..=80 => 1,
+            81..=160 => 2,
             _ => 3,
         };
 
@@ -222,7 +222,7 @@ impl Engine {
                 if Some(m) == transposition.map(|t| t.best()) {
                     (m, Value::upper())
                 } else if Self::KILLERS.with_borrow(|ks| ks.contains(ply, pos.turn(), m)) {
-                    (m, Value::new(100))
+                    (m, Value::new(40))
                 } else if m.is_quiet() {
                     (m, Value::new(0))
                 } else {
@@ -308,7 +308,7 @@ impl Engine {
         'id: for d in depth.get()..=limit.get() {
             let mut overtime = time.end - time.start;
             let mut depth = Depth::new(d);
-            let mut delta: i16 = 24;
+            let mut delta: i16 = 10;
 
             let (mut lower, mut upper) = match d {
                 ..=4 => (Score::lower(), Score::upper()),
diff --git a/lib/search/ply.rs b/lib/search/ply.rs
index 47a956f4..6efd4b69 100644
--- a/lib/search/ply.rs
+++ b/lib/search/ply.rs
@@ -11,7 +11,7 @@ unsafe impl Integer for PlyRepr {
     const MIN: Self::Repr = -Self::MAX;
 
     #[cfg(not(test))]
-    const MAX: Self::Repr = 127;
+    const MAX: Self::Repr = 95;
 
     #[cfg(test)]
     const MAX: Self::Repr = 3;
diff --git a/lib/search/score.rs b/lib/search/score.rs
index dd758814..acf77934 100644
--- a/lib/search/score.rs
+++ b/lib/search/score.rs
@@ -10,7 +10,7 @@ pub struct ScoreRepr(#[cfg_attr(test, strategy(Self::MIN..=Self::MAX))] <Self as
 unsafe impl Integer for ScoreRepr {
     type Repr = i16;
     const MIN: Self::Repr = -Self::MAX;
-    const MAX: Self::Repr = 8191;
+    const MAX: Self::Repr = 4095;
 }
 
 /// The minimax score.
@@ -50,7 +50,7 @@ impl Perspective for Score {
 }
 
 impl Binary for Score {
-    type Bits = Bits<u16, 14>;
+    type Bits = Bits<u16, 13>;
 
     #[inline(always)]
     fn encode(&self) -> Self::Bits {
diff --git a/lib/search/transposition.rs b/lib/search/transposition.rs
index f2f5c60c..a8c7dba6 100644
--- a/lib/search/transposition.rs
+++ b/lib/search/transposition.rs
@@ -102,7 +102,7 @@ impl Transposition {
 }
 
 impl Binary for Transposition {
-    type Bits = Bits<u64, 38>;
+    type Bits = Bits<u64, 37>;
 
     #[inline(always)]
     fn encode(&self) -> Self::Bits {
@@ -125,7 +125,7 @@ impl Binary for Transposition {
     }
 }
 
-type Signature = Bits<u32, 26>;
+type Signature = Bits<u32, 27>;
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 #[cfg_attr(test, derive(test_strategy::Arbitrary))]