Remove cap from space score contribution and increase bonus

STC
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 58462 W: 10615 L: 10558 D: 37289

LTC
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 65061 W: 8539 L: 8477 D: 48045

It is worth noting that an attempt to only increase the bonus passed STC but failed LTC, and
an attempt to remove the cap without increasing the bonus is still running at STC, but will probably fail after more than 100k.

Bench: 6188591

Closes #1063

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index a4b3c3383bdbb4cb897880053f96ec0fb1e42e5d..23ab62ec5ab178123612d14fea547c3e36daad06 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -720,10 +720,9 @@ namespace {
 
     // ...count safe + (behind & safe) with a single popcount.
     int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
 
     // ...count safe + (behind & safe) with a single popcount.
     int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));

-    bonus = std::min(16, bonus);

     int weight = pos.count<ALL_PIECES>(Us) - 2 * ei.pe->open_files();
 
     int weight = pos.count<ALL_PIECES>(Us) - 2 * ei.pe->open_files();
 

-    return make_score(bonus * weight * weight / 18, 0);
+    return make_score(bonus * weight * weight / 16, 0);

   }
 
 
   }