Arasan 20.3 is available from https://www.arasanchess.org.
Changes in Arasan 20.3:
1) Change queen mobility scoring: square reach beyond 23 squares gets
same score.
2) Re-work scoring for material imbalance with pawns.
3) Bug fixes for EPD/FEN handling (mostly affects utility programs).
4) Bug fixes for bitbases. Mate scores from bitbases were not being
transmitted to the search. Also bitbase scores were being added to
other eval terms which are not relevant for KPK.
5) Syzygy code (Fathom) is imported as a git submodule now.
6) Code restructuring, move piece values into Param class.
7) Change eval scale so Pawn value = 128 (vs. 1000 in 20.2).
8) Implement UCI "searchmoves" option to "go" command.
9) Bug fixes in parameter tuner.
10) If special-case endgame detected, skip other endgame scoring and
just use the special-case code.
11) In UCI MultiPV mode, ensure bestmove that is eventually sent is the
highest-scoring move, and re-order PVs if necessary so that they are
in decreasing score order.
12) Implement BMI2 (PEXT/PDEP) attack computation.
13) Change evasion pruning in qsearch.
14) Pack hash entries into 2 64-bits words instead of 3.
This is close to, but not identical with, the version that is playing in TCEC 10.
In my testing it is measurably stronger than 20.2, but not by a whole lot.
--Jon
Arasan 20.3
Moderators: hgm, Rebel, chrisw
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- Location: http://www.arasanchess.org
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- Location: Auckland, NZ
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Re: Arasan 20.3
Thanks once again Jon!jdart wrote:Arasan 20.3 is available from https://www.arasanchess.org.
Changes in Arasan 20.3:
1) Change queen mobility scoring: square reach beyond 23 squares gets
same score.
2) Re-work scoring for material imbalance with pawns.
3) Bug fixes for EPD/FEN handling (mostly affects utility programs).
4) Bug fixes for bitbases. Mate scores from bitbases were not being
transmitted to the search. Also bitbase scores were being added to
other eval terms which are not relevant for KPK.
5) Syzygy code (Fathom) is imported as a git submodule now.
6) Code restructuring, move piece values into Param class.
7) Change eval scale so Pawn value = 128 (vs. 1000 in 20.2).
8) Implement UCI "searchmoves" option to "go" command.
9) Bug fixes in parameter tuner.
10) If special-case endgame detected, skip other endgame scoring and
just use the special-case code.
11) In UCI MultiPV mode, ensure bestmove that is eventually sent is the
highest-scoring move, and re-order PVs if necessary so that they are
in decreasing score order.
12) Implement BMI2 (PEXT/PDEP) attack computation.
13) Change evasion pruning in qsearch.
14) Pack hash entries into 2 64-bits words instead of 3.
This is close to, but not identical with, the version that is playing in TCEC 10.
In my testing it is measurably stronger than 20.2, but not by a whole lot.
--Jon
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- Posts: 782
- Joined: Tue Dec 01, 2009 11:10 am
Re: Arasan 20.3
At the times, when Windows 95 came out, I started with computers, and verry quick I also startetd with chess engines, chess programms.
One of the first free chess engines I saw was Arasan. It had its own interface, ready to play. I liked IT !
I am impressed that it is still under developement. Evertime I hear from Arasan updates, I remember the times of Win95 and the many nights I spent with reinstalling OS
Clemens Keck
One of the first free chess engines I saw was Arasan. It had its own interface, ready to play. I liked IT !
I am impressed that it is still under developement. Evertime I hear from Arasan updates, I remember the times of Win95 and the many nights I spent with reinstalling OS
Clemens Keck
jdart wrote:Arasan 20.3 is available from https://www.arasanchess.org.
Changes in Arasan 20.3:
1) Change queen mobility scoring: square reach beyond 23 squares gets
same score.
2) Re-work scoring for material imbalance with pawns.
3) Bug fixes for EPD/FEN handling (mostly affects utility programs).
4) Bug fixes for bitbases. Mate scores from bitbases were not being
transmitted to the search. Also bitbase scores were being added to
other eval terms which are not relevant for KPK.
5) Syzygy code (Fathom) is imported as a git submodule now.
6) Code restructuring, move piece values into Param class.
7) Change eval scale so Pawn value = 128 (vs. 1000 in 20.2).
8) Implement UCI "searchmoves" option to "go" command.
9) Bug fixes in parameter tuner.
10) If special-case endgame detected, skip other endgame scoring and
just use the special-case code.
11) In UCI MultiPV mode, ensure bestmove that is eventually sent is the
highest-scoring move, and re-order PVs if necessary so that they are
in decreasing score order.
12) Implement BMI2 (PEXT/PDEP) attack computation.
13) Change evasion pruning in qsearch.
14) Pack hash entries into 2 64-bits words instead of 3.
This is close to, but not identical with, the version that is playing in TCEC 10.
In my testing it is measurably stronger than 20.2, but not by a whole lot.
--Jon
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- Posts: 364
- Joined: Sat Jun 13, 2015 10:08 am
- Location: Poland
- Full name: Dariusz Domagała
Re: Arasan 20.3
Thank You Jon for this amazing engine.
I will testing it today on my mac )
I will testing it today on my mac )
Regards, Darius
https://chessengeria.eu
https://chessengeria.eu
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- Joined: Mon Feb 11, 2008 3:53 pm
- Location: Denmark
- Full name: Damir Desevac
Re: Arasan 20.3
Thanks Jon for continous improvement of your engine. Do you have any estimation how much this version is stronger than 10.2 version ?
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- Location: http://www.arasanchess.org
Re: Arasan 20.3
I guess you mean 20.2. I would guess +10 ELO or so on an arbitrary rating scale where 20.2 is about 2400 ELO. So a bit more on the CCRL or CEGT scale, probably.estimation how much this version is stronger than 10.2 version
Also note: I don't really put any effort into optimizing or testing the MacOS version. All I do is build it and do a little sanity checking.
--Jon
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- Joined: Mon Feb 11, 2008 3:53 pm
- Location: Denmark
- Full name: Damir Desevac
Re: Arasan 20.3
Yes I meant 20.2 version. Sorry was a mistake on my part.
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- Joined: Wed Mar 08, 2006 8:57 pm
- Location: Redmond, WA USA
Re: Arasan 20.3
It's always a good day when there is a new Arasan.
Taking ideas is not a vice, it is a virtue. We have another word for this. It is called learning.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.
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- Joined: Wed Oct 01, 2008 6:33 am
- Location: Regensburg, Germany
- Full name: Guenther Simon
Re: Arasan 20.3
Thanks a lot Jon. It's incredible that ArasanX is still a living project after decades!jdart wrote:Arasan 20.3 is available from https://www.arasanchess.org.
Changes in Arasan 20.3:
1) Change queen mobility scoring: square reach beyond 23 squares gets
same score.
2) Re-work scoring for material imbalance with pawns.
3) Bug fixes for EPD/FEN handling (mostly affects utility programs).
4) Bug fixes for bitbases. Mate scores from bitbases were not being
transmitted to the search. Also bitbase scores were being added to
other eval terms which are not relevant for KPK.
5) Syzygy code (Fathom) is imported as a git submodule now.
6) Code restructuring, move piece values into Param class.
7) Change eval scale so Pawn value = 128 (vs. 1000 in 20.2).
8) Implement UCI "searchmoves" option to "go" command.
9) Bug fixes in parameter tuner.
10) If special-case endgame detected, skip other endgame scoring and
just use the special-case code.
11) In UCI MultiPV mode, ensure bestmove that is eventually sent is the
highest-scoring move, and re-order PVs if necessary so that they are
in decreasing score order.
12) Implement BMI2 (PEXT/PDEP) attack computation.
13) Change evasion pruning in qsearch.
14) Pack hash entries into 2 64-bits words instead of 3.
This is close to, but not identical with, the version that is playing in TCEC 10.
In my testing it is measurably stronger than 20.2, but not by a whole lot.
--Jon
https://rwbc-chess.de
trollwatch:
Talkchess nowadays is a joke - it is full of trolls/idiots/people stuck in the pleistocene > 80% of the posts fall into this category...
trollwatch:
Talkchess nowadays is a joke - it is full of trolls/idiots/people stuck in the pleistocene > 80% of the posts fall into this category...