From c0570a8bd119f10e0300aadbbe46dbffe5ed4df1 Mon Sep 17 00:00:00 2001
From: dhb <1084714805@qq.com>
Date: Fri, 14 Jun 2024 14:24:01 +0800
Subject: [PATCH] use statScore to adjust futility margin (div 256 clamp 0)

test r15
---
 Rapfi/search/ab/parameter.h | 6 ++++--
 Rapfi/search/ab/search.cpp  | 7 ++++++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/Rapfi/search/ab/parameter.h b/Rapfi/search/ab/parameter.h
index d21ff68c..8a221b63 100644
--- a/Rapfi/search/ab/parameter.h
+++ b/Rapfi/search/ab/parameter.h
@@ -67,10 +67,12 @@ constexpr Value razorMargin(Depth d)
 
 /// Static futility pruning depth & margins
 template <Rule R>
-constexpr Value futilityMargin(Depth d, bool noTTCutNode, bool improving)
+constexpr Value futilityMargin(Depth d, bool noTTCutNode, bool improving, int statScore)
 {
     constexpr int FutilityScale[RULE_NB] = {63, 61, 78};
-    return Value(std::max(int((FutilityScale[R] - 13 * noTTCutNode) * (d - improving)), 0));
+    int           margin =
+        int((FutilityScale[R] - 13 * noTTCutNode) * (d - (1 + improving))) - statScore / 256;
+    return Value(std::max(margin, 0));
 }
 
 /// Null move pruning margin
diff --git a/Rapfi/search/ab/search.cpp b/Rapfi/search/ab/search.cpp
index d8515780..d5dc1183 100644
--- a/Rapfi/search/ab/search.cpp
+++ b/Rapfi/search/ab/search.cpp
@@ -841,7 +841,12 @@ Value search(Board &board, SearchStack *ss, Value alpha, Value beta, Depth depth
     // Step 8. Futility pruning: child node (~70 elo)
     if (!PvNode && eval < VALUE_MATE_IN_MAX_PLY  // Do not return unproven wins
         && beta > VALUE_MATED_IN_MAX_PLY         // Confirm non-losing move exists
-        && eval - futilityMargin<Rule>(depth - 1, cutNode && !ttHit, improvement > 0) >= beta
+        && eval
+                   - futilityMargin<Rule>(depth,
+                                          cutNode && !ttHit,
+                                          improvement > 0,
+                                          (ss - 1)->statScore)
+               >= beta
         && !((ss - 2)->moveP4[self] >= E_BLOCK4 && (ss - 4)->moveP4[self] >= E_BLOCK4))
         return eval;