They are always true anyway and are heavy used file scope
variables where there could be SMP contention. Although read only.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
After proof testing on 3 different engines these
are the results:
Stockfish - Toga II 1.4.1SE +130 -132 =132 49.75%
Stockfish - Deep Sieng 3.0 +145 -110 =150 54.45%
Stockfish - HIARCS 12 MP +94 -149 =150 43.00%
So it seems no regressions occurs, although also no
improvment. But anyhow this patch increases Stockfish
strenght against itself, so merge it.
Note that this patch not only adds back razoring at depth
one, but also increases razor depth limit from 3 to 4
because hard coded depth 4 limit is no more overwritten
by UCI parameter that otherwise defaults to 3.
Because futility margins array has a fixed size we cannot
arbitrarly choose or change the SelectiveDepth parameter,
otherwise we have a crash for values bigger then array size.
On the other hand tweaking of this parameter requires some
modification to the hardcoded margins, so makes sense to hard
code also this very bounded one.
Who wants to experiment is of course free to change the sources.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
When testing at 1'+0" time control results are still
reasonably good. We have made two sessions on two
different PC.
After 840 games Mod - Orig: +221 -194 =425 +10 ELO (two CPU)
After 935 games Mod - Orig: +246 -222 =467 +9 ELO (single CPU)
So it seems that with fast CPU and/or longer time controls
benefits of the patch are a bit reduced. This could be due
to the fact that only 3% of nodes are pruned by razoring at
depth one and these nodes are very swallow ones, mostly get
pruned anyway with only a slightly additional cost, even
without performing any do_move() call.
Another reason is that sometime (0,3%% of cases) a possible
good move is missed typically in positions when moving side
gives check, as example in the following one
3r2k1/pbpp1nbp/1p6/3P3q/6RP/1P4P1/P4Pb1/3Q2K1 w - -
The winning move Rxg7+ is missed.
Bottom line is that patch seems good for blitz times, perhaps
also for longer times. We should test against a third engine
(Toga ?) to have a final answer regarding this new setup.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Restructure RazorMargins and FutilityMargins arrays so that their
values can be more easily tuned.
Add RazorApprMargins array which replaces razorAtDepthOne concept,
because setting RazorApprMargin very high value at ply one is
same as not razoring there at all.
Comment out setting razoring and futility margins through uci to
avoid errors while tuning.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
If a variable will be populated reading an UCI option
then do not hard code its default values.
This avoids misleadings when reading the sources.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Sometimes C++ can be really bad!
In this case an hard coded c string selects Option c'tor
with int argument instead of the std::string one becuase
it is considered a better matching by the compiler.
Fix the bug changing the argument type from std::string to
const char* so to be a better match then the int one.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Store boolean values as "1" and "0" instead of "true" and "false"
and convert back to UCI protocol convention when needed.
This is simpler then the other way around.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Apart from the teoretical speed increase, the main reason
of this patch is a good amount of code cleanup.
Note that now UCI options are printed in alphabetical
order and not in insertion order as before. Next patch
will take care of restoring old behaviour.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It does not seem to clearly improve things and
in any case is disabled by default, so retire for now.
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>
Is a new evaluation rule that gives bonus in midgame
to the side that has more space behind pawns for its
minor pieces.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
When an engine is in deep trouble at few
seconds from time limit then giveup without
fighting anymore.
This is used to reduce "lucky draws" and time pressure
blunders noises that can obfuscate results during tests
blitz games (typical one minute games).
Goal of this technique is to reduce number of matches
needed to reliably prove then an engine A is stronger
then an opponent B.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
After testing and comparing output with standard Glaurung
a couple of issues arised.
A default value was wrong and init_uci_options() missed a couple
of stringify() calls. Also storing bool values as "false" and "true"
needs some care.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Instead of old-style C string functions use standard
library to greatly streamline the implementation.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
