Find squares attacked by slider checkers, we will
remove them from king evasions set so to avoid a couple
of cycles in the slow king evasions legality check loop.
Not a biggie, but now generate_evasions() is faster then
generate_non_captures(), before was slower.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
When we generate checks one case is missing: generation
of castling moves that give check to the opponent king.
This is a very rare case but anyway it is a case
and we can do this without slowing down the common
case of no castling checks.
So this is the patch.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Go back to original direct assignment, this allows to
add an include in pawns.h to teach about memset()
This fix a compile error under Ubuntu.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
For queen mobility could be bigger then 15, so
we need count_1s() not count_1s_max_15().
This bug was introduced by patch:
"Group common evaluate code" of 24/9/2008
So it's almost 4 months and two release old!
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Do not consider squares protected by enemy pawns
in mobility evaluation.
This reduces the mobility value by about 15%
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This is somewhat taken from Stockfish 1.2 Default,
only the razoring thresold are updated, not the
razoring depth.
At the end razoring is a bit more aggressive. Results
seems slightly positive.
After 999 games +239 =536 -224 Elo +5
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Optimistic razoring settings. It is stronger with
most engines but weaker with someones.
The default is instead more solid and uniform with all
the opponents.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Add also the possibility to razor at ply one.
It is disable dby default but it seems stronger
against Stockfish itself. It is still not clear if
is stronger against other engines. By now leave
disabled.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Less prune at the bottom and at the middle, a bit more
at the top.
After 747 games: +215 =345 -187 +13 elo
Also introduced a vector of margins, now that start to be a lot
it is a more flexible solution.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Because razoring verification after qsearch() cuts more
then 40% of candidates, do not waste a costly qsearch for
nodes at depth one that will be probably discarded anyway
by futility.
Also tight razoring conditions to keep dangerous false
negatives below 0,05%. Still not clear if it is enough.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Bug fix merged from Glaurung 2.2 for search_pv()
Added the same fix also to sp_search_pv() where
was missing.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
