From 1b6975ac4151d503ca48c9d5d4bd18d5fa11f4b9 Mon Sep 17 00:00:00 2001
From: Mapika <marosimark251@gmail.com>
Date: Sat, 17 May 2025 18:01:25 +0200
Subject: [PATCH] Add quiet move streak tracking to search stack

Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 109344 W: 28473 L: 28053 D: 52818
Ptnml(0-2): 320, 12756, 28085, 13206, 305
https://tests.stockfishchess.org/tests/view/6828c43e6ec7634154f99a10

Passed LTC:
LLR: 2.96 (-2.94,2.94) <0.50,2.50>
Total: 76308 W: 19721 L: 19323 D: 37264
Ptnml(0-2): 39, 8145, 21386, 8547, 37
https://tests.stockfishchess.org/tests/view/6828f65a6ec7634154f99b72

closes https://github.com/official-stockfish/Stockfish/pull/6066

Bench: 2161814
---
 AUTHORS        | 1 +
 src/search.cpp | 5 +++++
 src/search.h   | 1 +
 3 files changed, 7 insertions(+)

diff --git a/AUTHORS b/AUTHORS
index f1675860..8caa2285 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -148,6 +148,7 @@ Lucas Braesch (lucasart)
 Lyudmil Antonov (lantonov)
 Maciej Żenczykowski (zenczykowski)
 Malcolm Campbell (xoto10)
+Mark Marosi (Mapika)
 Mark Tenzer (31m059)
 marotear
 Mathias Parnaudeau (mparnaudeau)
diff --git a/src/search.cpp b/src/search.cpp
index 857a8d47..0af54b4f 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1004,6 +1004,8 @@ moves_loop:  // When in check, search starts here
         movedPiece = pos.moved_piece(move);
         givesCheck = pos.gives_check(move);
 
+        (ss + 1)->quietMoveStreak = (!capture && !givesCheck) ? (ss->quietMoveStreak + 1) : 0;
+
         // Calculate new depth for this move
         newDepth = depth - 1;
 
@@ -1198,6 +1200,9 @@ moves_loop:  // When in check, search starts here
         if ((ss + 1)->cutoffCnt > 2)
             r += 1036 + allNode * 848;
 
+        if (!capture && !givesCheck && ss->quietMoveStreak >= 2)
+            r += (ss->quietMoveStreak - 1) * 50;
+
         // For first picked move (ttMove) reduce reduction
         else if (move == ttData.move)
             r -= 2006;
diff --git a/src/search.h b/src/search.h
index 0c041c82..5caff10e 100644
--- a/src/search.h
+++ b/src/search.h
@@ -76,6 +76,7 @@ struct Stack {
     int                         cutoffCnt;
     int                         reduction;
     bool                        isPvNode;
+    int                         quietMoveStreak;
 };