a) Reduce PSQT values along the long diagonals on non-central squares
and increase the LongDiagonal bonus accordingly. The effect is to penalise
bishops on the long diagonal which can not "see" the 2 central squares.
The "good" bishops still have more or less the same bonus as current master.
b) For a bishop on a central square, because of the "| s" term in the code,
the LongDiagonalBonus was always given. So while being there, remove the "| s"
and compensate the central Bishop PSQT accordingly.
Passed STC
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 44498 W: 9658 L: 9323 D: 25517
http://tests.stockfishchess.org/tests/view/5b8992770ebc592cf2748942
Passed LTC
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 63092 W: 10324 L: 9975 D: 42793
http://tests.stockfishchess.org/tests/view/5b89a17a0ebc592cf2748b59
Closes https://github.com/official-stockfish/Stockfish/pull/1760
bench: 4693901
After a session of tuning for King Psqt I got some new values, which was later
tweaked manually by me Fauzi, to result in an Elo-gain patch which seems to scale
pretty well:
STC: LLR: -2.96 (-2.94,2.94) [0.00,4.00]
Total: 100653 W: 22550 L: 22314 D: 55789 [Yellow patch]
LTC: LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 147079 W: 25584 L: 24947 D: 96548 [Green Patch]
Bench: 4669050
To more clearly distinguish them from "const" local variables, this patch
defines compile-time local constants as constexpr. This is consistent with
the definition of PvNode as constexpr in search() and qsearch(). It also
makes the code more robust, since the compiler will now check that those
constants are indeed compile-time constants.
We can go even one step further and define all the evaluation and search
compile-time constants as constexpr.
In generate_castling() I replaced "K" with "step", since K was incorrectly
capitalised (in the Chess960 case).
In timeman.cpp I had to make the non-local constants MaxRatio and StealRatio
constepxr, since otherwise gcc would complain when calculating TMaxRatio and
TStealRatio. (Strangely, I did not have to make Is64Bit constexpr even though
it is used in ucioption.cpp in the calculation of constexpr MaxHashMB.)
I have renamed PieceCount to pieceCount in material.h, since the values of
the array are not compile-time constants.
Some compile-time constants in tbprobe.cpp were overlooked. Sides and MaxFile
are not compile-time constants, so were renamed to sides and maxFile.
Non-functional change.
Implements renaming suggestions by Marco Costalba, Günther Demetz,
Gontran Lemaire, Ronald de Man, Stéphane Nicolet, Alain Savard,
Joost VandeVondele, Jerry Donald Watson, Mike Whiteley, xoto10,
and I hope that I haven't forgotten anybody.
Perpetual renaming thread for suggestions:
https://github.com/official-stockfish/Stockfish/issues/1426
No functional change.
Currently the NORTH/WEST/SOUTH/EAST values are of type Square, but conceptually they are not squares but directions. This patch separates these values into a Direction enum and overloads addition and subtraction to allow adding a Square to a Direction (to get a new Square).
I have also slightly trimmed the possible overloadings to improve type safety. For example, it would normally not make sense to add a Color to a Color or a Piece to a Piece, or to multiply or divide them by an integer. It would also normally not make sense to add a Square to a Square.
This is a non-functional change.
A tuning patch which cover the following changes:
increase the importance of queen and rook mobility in endgame and
decrease it in mg, since if we use the heavy pieces too early in the game
we will just make opponent develop their pieces by threatening ours.
King Psqt:
1)King will be encouraged more to stay in the first ranks in the MG
2)and will be encouraged more to go to the middle of the board/last ranks in the EG
Bishop scale better in EG
Logical changes on various psqt tables
1/6 of the changes of the last tuning session on mobility tables
STC: LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 227879 W: 41240 L: 40313 D: 146326
LTC : LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 167047 W: 21871 L: 21291 D: 123885
Bench: 5695960
Closes#1008
This patch tweaks some pawn values to favor flank attacks.
The first part of the patch increases the midgame psqt values of external pawns to launch more attacks (credits to user GuardianRM for this idea), while the second part increases the endgame connection values for pawns on upper ranks.
Passed STC:
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 34997 W: 6328 L: 6055 D: 22614
and LTC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 13844 W: 1832 L: 1650 D: 10362
Bench: 5884767
Rename shift_bb() to shift(), and DELTA_S to SOUTH, etc.
to improve code readability, especially in evaluate.cpp
when they are used together:
old b = shift_bb<DELTA_S>(pos.pieces(PAWN))
new b = shift<SOUTH>(pos.pieces(PAWN))
While there fix some small code style issues.
No functional change.
Instead of crafting a clever formula to calculate the array offset, simply use a
3 dimensional array. Remove the comment while at it, because now the code is
self-documenting.
No functional change.
Resolves#344
Use symmetry along vertical middle axis of the board
to reduce the number of parameters.
For instance psqt value of SQ_A5 == SQ_A4 and value of
SQ_F8 == SQ_F1.
This is always true, at least until now nobody came in
with an asymmetric psqt table that worked.
Original patch by Lucas.
No functional change.
Easier for tuning psq tables:
TUNE(myParameters, PSQT::init);
Also move PSQT code in a new *.cpp file, and retire the
old and hacky psqtab.h that required to be included only
once to work correctly, this is not idiomatic for a header
file.
Give wide visibility to psq tables (previously visible only
in position.cpp), this will easy the use of psq tables outside
Position, for instance in move ordering.
Finally trivial code style fixes of the latest patches.
Original patch of Lucas Braesch.
No functional change.
