From e852d9880a6d3e25d92b6db8216f497ad98c2c57 Mon Sep 17 00:00:00 2001
From: Michael Chaly <Vizvezdenec@gmail.com>
Date: Tue, 4 Feb 2025 22:14:13 +0300
Subject: [PATCH] Reduce less for positions without tt move

Continuation of work on scaling.
In line with previous scaling patches this one massively reduces
reduction for moves that don't go thru lmr for position without a tt
move.

Passed VVLTC with STC bounds:
https://tests.stockfishchess.org/tests/view/679fd2450774dfd78deb12b2
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 74718 W: 19354 L: 19042 D: 36322
Ptnml(0-2): 5, 6724, 23595, 7024, 11

Passed VVLTC with LTC bounds:
https://tests.stockfishchess.org/tests/view/67a009930774dfd78deb2346
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 82638 W: 21587 L: 21212 D: 39839
Ptnml(0-2): 15, 7476, 25953, 7869, 6

closes https://github.com/official-stockfish/Stockfish/pull/5860

Bench: 2887850
---
 src/search.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/search.cpp b/src/search.cpp
index b8221715..99aff5e9 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1241,7 +1241,7 @@ moves_loop:  // When in check, search starts here
         {
             // Increase reduction if ttMove is not present
             if (!ttData.move)
-                r += 2117;
+                r += 1111;
 
             // Note that if expected reduction is high, we reduce search depth here
             value = -search<NonPV>(pos, ss + 1, -(alpha + 1), -alpha,