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Use a formula for chain membership bonus 

Passed both short TC:
LLR: 2.96 (-2.94,2.94) [-1.50,4.50]
Total: 5087 W: 1072 L: 951 D: 3064

And long TC:
LLR: 2.95 (-2.94,2.94) [0.00,6.00]
Total: 28620 W: 5042 L: 4798 D: 18780

bench: 7995098
sf_dd_base
Ralph Stößer 2013-10-31 06:02:17 +01:00 committed by Marco Costalba
parent 3cc47edf62
commit e8f9447b11
3 changed files with 20 additions and 10 deletions
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1
src/main.cpp
View File

@ -37,6 +37,7 @@ int main(int argc, char* argv[]) {
Position::init();
Bitbases::init_kpk();
Search::init();
Pawns::init();
Eval::init();
Threads.init();
TT.set_size(Options["Hash"]);

28
src/pawns.cpp
View File

@ -51,16 +51,8 @@ namespace {
{ S(20, 28), S(29, 31), S(33, 31), S(33, 31),
S(33, 31), S(33, 31), S(29, 31), S(20, 28) }};
// Pawn chain membership bonus by file
const Score ChainMember[FILE_NB][RANK_NB] = {
{ S(0, 0), S(14, 0), S(16, 4), S(18, 9), S(28, 28), S(52, 104), S(118, 236) },
{ S(0, 0), S(16, 0), S(18, 5), S(20, 10), S(30, 30), S(54, 108), S(120, 240) },
{ S(0, 0), S(16, 0), S(18, 5), S(20, 10), S(30, 30), S(54, 108), S(120, 240) },
{ S(0, 0), S(17, 0), S(19, 6), S(22, 11), S(33, 33), S(59, 118), S(127, 254) },
{ S(0, 0), S(17, 0), S(19, 6), S(22, 11), S(33, 33), S(59, 118), S(127, 254) },
{ S(0, 0), S(16, 0), S(18, 5), S(20, 10), S(30, 30), S(54, 108), S(120, 240) },
{ S(0, 0), S(16, 0), S(18, 5), S(20, 10), S(30, 30), S(54, 108), S(120, 240) },
{ S(0, 0), S(14, 0), S(16, 4), S(18, 9), S(28, 28), S(52, 104), S(118, 236) }};
// Pawn chain membership bonus by file and rank (initialized by formula)
Score ChainMember[FILE_NB][RANK_NB];
// Candidate passed pawn bonus by rank
const Score CandidatePassed[RANK_NB] = {
@ -199,6 +191,22 @@ namespace {
namespace Pawns {
/// init() initializes some tables by formula instead of hard-code their values
void init() {
const int chainByFile[8] = { 1, 3, 3, 4, 4, 3, 3, 1 };
int bonus;
for (Rank r = RANK_1; r < RANK_8; ++r)
for (File f = FILE_A; f <= FILE_H; ++f)
{
bonus = r * (r-1) * (r-2) + chainByFile[f] * (r/2 + 1);
ChainMember[f][r] = make_score(bonus, bonus);
}
}
/// probe() takes a position object as input, computes a Entry object, and returns
/// a pointer to it. The result is also stored in a hash table, so we don't have
/// to recompute everything when the same pawn structure occurs again.

1
src/pawns.h
View File

@ -73,6 +73,7 @@ struct Entry {
typedef HashTable<Entry, 16384> Table;
void init();
Entry* probe(const Position& pos, Table& entries);
}