Changes in Arasan 17.4:
1) Deeper LMR (and different reduction formula). After a LMR search
fails high, first re-search with no reduction but zero width bounds,
then only do a full-width, full-depth search.
2) Reduce q-search pruning margin.
3) Bug fix for pondering in Winboard mode. Engine could fail to ponder
again after a successful ponder.
4) Bug fixes to Winboard analysis mode.
5) Bug fix in Board::wouldAttack.
6) Widen somewhat the range of conditions that will prevent
a move from being pruned, based on the null-move threat (if
there is one).
7) Simpify & tune late-move pruning code and remove vestiges of history
pruning.
8) Add .EXPORT_ALL_VARIABLES target to Linux Makefile, to make build
targets work that depend on redefining CC etc.
Some test results (Linux, 1 CPU, 400 games, 4+1 time control, 8-move opening book):
Code: Select all
Rank Name Elo + - games score oppo. draws
1 Arasan 17.4 2415 14 14 400 55% 2385 54%
2 Arasan-17.3 2385 14 14 400 45% 2415 54%