opelly/Stockfish
1
0
Fork 0
mirror of https://github.com/opelly27/Stockfish.git synced 2026-05-20 07:27:46 +00:00
Code Issues Packages Projects Releases Wiki Activity

Linear Protector bonus by distance

Browse Source 
Replacing the old Protector table with a simple linear formula which takes into account a different slope for each different piece type.

The idea of this simplification of Protector is originated by Alain (Rocky)

STC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 70382 W: 12859 L: 12823 D: 44700

LTC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 61554 W: 8098 L: 8031 D: 45425

Bench: 6107863

Closes #1099
This commit is contained in:
FauziAkram
2017-05-07 21:03:59 -07:00
committed by Joona Kiiski
parent ae97941628
commit 6b4959e3e0
2 changed files with 7 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/evaluate.cpp
+3 -10
View File
@@ -174,14 +174,8 @@ namespace {
S(-20,-12), S( 1, -8), S( 2, 10), S( 9, 10)
};
// Protector[PieceType-2][distance] contains a protecting bonus for our king,
// indexed by piece type and distance between the piece and the king.
const Score Protector[][8] = {
{ S(0, 0), S( 7, 9), S( 7, 1), S( 1, 5), S(-10,-4), S( -1,-4), S( -7,-3), S(-16,-10) }, // Knight
{ S(0, 0), S(11, 8), S(-7,-1), S(-1,-2), S( -1,-7), S(-11,-3), S( -9,-1), S(-16, -1) }, // Bishop
{ S(0, 0), S(10, 0), S(-2, 2), S(-5, 4), S( -6, 2), S(-14,-3), S( -2,-9), S(-12, -7) }, // Rook
{ S(0, 0), S( 3,-5), S( 2,-5), S(-4, 0), S( -9,-6), S( -4, 7), S(-13,-7), S(-10, -7) } // Queen
};
// KingProtector[PieceType-2] * "distance to own king" determines a bonus for each piece.
const Score KingProtector[] = {S(-3, -5), S(-4, -3), S(-3, 0), S(-1, 1) };
// Assorted bonuses and penalties used by evaluation
const Score MinorBehindPawn = S( 16, 0);
@@ -299,8 +293,7 @@ namespace {
mobility[Us] += MobilityBonus[Pt-2][mob];
// Bonus for this piece as a king protector
score += Protector[Pt-2][distance(s, pos.square<KING>(Us))];
score += KingProtector[Pt-2] * distance(s, pos.square<KING>(Us));
if (Pt == BISHOP || Pt == KNIGHT)
{