From 5596492f6ed72ebc52a4d0f65bed483568e48918 Mon Sep 17 00:00:00 2001
From: VoyagerOne <excelgeek@gmail.com>
Date: Mon, 15 Aug 2016 11:19:21 -0400
Subject: [PATCH] Simplify IID

STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 30468 W: 5687 L: 5582 D: 19199
http://tests.stockfishchess.org/tests/view/57b1ddd80ebc591c761f63e2

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 87406 W: 11756 L: 11725 D: 63925
http://tests.stockfishchess.org/tests/view/57b212590ebc591c761f63f9

bench: 6554900
---
 src/search.cpp | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/search.cpp b/src/search.cpp
index 9eeafbda..3dfd5d6d 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -801,13 +801,12 @@ namespace {
     }
 
     // Step 10. Internal iterative deepening (skipped when in check)
-    if (    depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY)
+    if (    depth >= 6 * ONE_PLY
         && !ttMove
         && (PvNode || ss->staticEval + 256 >= beta))
     {
-        Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4);
         ss->skipEarlyPruning = true;
-        search<NT>(pos, ss, alpha, beta, d, cutNode);
+        search<NT>(pos, ss, alpha, beta, 3 * depth / 4 - 2 * ONE_PLY, cutNode);
         ss->skipEarlyPruning = false;
 
         tte = TT.probe(posKey, ttHit);
-- 
2.39.2