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Remove RedundantMajor

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But compensate by reducing rook and queen
value by 53 = (160 / 3)

Material imbalances are affected as follows:

       Red. Major   Rook  Queen  Total
QRR      +160      -2*53    -53     +1
QR       +160        -53    -53    +54
RR       +160      -2*53      0    +54
R           0        -53      0    -53
Q           0          0    -53    -53

so that the imbalance changes by at most 54 + 53 = 107 units.
This corresponds to appromximately 3.5cp in the final evaluation.

Verified with fixed number 40000 games at both short
and long TC it does not regress.

Short TC 15+0.05
ELO: 1.93 +-2.1 (95%) LOS: 96.6%
Total: 40000 W: 7520 L: 7298 D: 25182

Long TC 60+0.05
ELO: -0.33 +-1.9 (95%) LOS: 36.5%
Total: 39663 W: 6067 L: 6105 D: 27491

bench: 6703846
This commit is contained in:
Chris Caino
2013-11-07 18:28:57 +00:00
committed by Marco Costalba
parent e4d34e1815
commit 3ed86ed3f9
1 changed files with 1 additions and 6 deletions
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7
src/material.cpp
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@@ -35,10 +35,9 @@ namespace {
const int NoPawnsSF[4] = { 6, 12, 32 }; const int NoPawnsSF[4] = { 6, 12, 32 };
// Polynomial material balance parameters // Polynomial material balance parameters
const Value RedundantMajor = Value(160);
// pair pawn knight bishop rook queen // pair pawn knight bishop rook queen
const int LinearCoefficients[6] = { 1852, -162, -1122, -183, 302, 1 }; const int LinearCoefficients[6] = { 1852, -162, -1122, -183, 249, -52 };
const int QuadraticCoefficientsSameColor[][PIECE_TYPE_NB] = { const int QuadraticCoefficientsSameColor[][PIECE_TYPE_NB] = {
// pair pawn knight bishop rook queen // pair pawn knight bishop rook queen
@@ -105,10 +104,6 @@ namespace {
int pt1, pt2, pc, v; int pt1, pt2, pc, v;
int value = 0; int value = 0;
// Penalty for major piece redundancy
if (pieceCount[Us][ROOK] + pieceCount[Us][QUEEN] > 1)
value -= RedundantMajor;
// Second-degree polynomial material imbalance by Tord Romstad // Second-degree polynomial material imbalance by Tord Romstad
for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1) for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
{ {