Hella G?bor,
G?bor Szots wrote:Hi (Franck),
At the bottom of the ini file of the new Pharaon there are some lines which were not there in previous versions. Can you explain what role these settings play and if it is advisable to change them?
G?bor
Here is some explanations about those options :
USE_IID=TRUE
Enables Internal Iterative Deepening (IID) to improve move ordering.
IID was not used in Pharaon v2.62, and this new feature seems to improve the engine by about 15/20 elo point.
Default value : TRUE
USE_PROFILER=FALSE
A built in (and very basic) profiler to check where Pharaon lose most of its time
Default value : FALSE
(should be set to TRUE only for testing purpose)
CHECK_MATE_THREAT_FROM_NULLMOVE=TRUE
Use Null Move to check if the opponent has a mate threat in one move.
If it is the case, spend more time in the position (by making an extnesion)
Default value : TRUE
Seems to improve the engine by 5/10 points, and can speed up dramatically (10x factor) some mate solving problems.
INCLUDE_CHECKINGMOVES_IN_QSEARCH=TRUE
Normally in its Quiescence Search, Pharaon only consider capture moves.
When this option is set to TRUE, it will also consider checking moves in the first ply of the Quiescence Search.
Default value : TRUE
Seems to improve slightly the engine (not sure).
BM_EXTENSION=FALSE
When set to TRUE, enables the Botvinnik - Markoff Extension.
This was discussed extensively in the CCC.
The basic idea is to extend when the opponent has the same threat 2 times in a row.
For Pharaon, it seems to weaken badly the engine, but I am sure there is something good to retrieve from it.
Default value : FALSE
ORDERING=hash;capture;killer;counter;check;historical
Indicates in which order we should sort the moves.
In the above exemple we'll use :
First : the move from the hastables (hash)
Then : the captures winning material (capture)
Then : the killer moves (killer)
Then : the counter move (counter)
Then : checking moves that don't lose material (check)
Then : historical moves (historical).
You can decide to remove some ordering technics, or to rearrange them.
The above order seems to give the better results.
Best regards+
Franck