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Re: Sargon 1978 UCI Available

Posted: Fri Jun 05, 2020 1:43 am
by Bill Forster
ThatsIt wrote: Thu Jun 04, 2020 3:11 pm Sargon is clueless regarding the 3-fold-repetition!
This is very true. From the project page https://github.com/billforsternz/retro-sargon

"However there's no doubt that in general the horizon effect, as it is called, is a massive limitation on the strength of an engine that does a full width, fixed depth search with no pruning. Sargon runs well enough. It plays ugly anti-positional chess, but it does try to mobilise it's pieces and it's pretty decent at tactics and will sometimes tear you apart in a complex middlegame if you don't pay attention. But then it might not be able to finish you off. Despite being able to search deeper [in endgames] it still doesn't understand endgames because promoting pawns takes so many ply. And even winning with say K+Q v K is beyond its horizon unless the opponent's king is already corralled with Sargon's king nearby. I am tempted to add a simple "king in a decreasing sized box" type heuristic to the scoring function to fix that - but that's not really software archaeology is it? A similar problem, probably fixable in the same way is that Sargon will sometimes drift and concede a draw by repeating moves even in an overwhelming position. This is a reflection of Sargon's scoring function, which doesn't have any positional knowledge. Sargon just tries to win material, and if that's not possible control more squares than the opponent. This was typical of the era, in the early days of chess programming the pioneers were delighted to find that minimax plus alpha beta and a simple material plus board control scoring function was sufficient to play at least reasonable chess. But it was only a starting point for real progress."
AdminX wrote: Thu Jun 04, 2020 11:37 am Or maybe not ... :D At depth 6 it crushed Tarrasch Toy. Appeared to be more tactically alert.
This is a little misleading because I didn't parse the depth parameter of the Go command when I implemented Tarrasch Toy 10 years ago. I know this because I adapted the UCI protocol handler from then to the new Sargon 1978 engine project, and this time my Arena testing showed the value of that parameter, so I implemented it for Sargon. So in your game Sargon will always use depth 6, and Tarrasch Toy 0.905 will just make a (bad) judgement call about what depth to go to. If you play a match with no depth specified and 15/20/25 minutes each plus increment as I did, you'll find Sargon 1978 outmatched. This is not surprising because (by coincidence only) Tarrasch Toy uses more or less exactly the same approach as Sargon 1978 (shallow, full width search plus SOMA), but Tarrasch Toy has a more elaborate scoring function, with quite a lot of chess heuristics (versus Sargon with nothing but material and board control). Tarrasch Toy uses C++ not assembly, but has fast lookup table based move generation (Sargon couldn't afford such luxuries) to compensate. Tarrasch Toy 0.906 is significantly stronger than Tarrasch Toy 0.905, mainly because of better time management, 0.906 at Elo 1492 is much stronger than Sargon 1978, 0.905 is still significantly stronger but my expertise at measuring these things precisely is non-existent unfortunately.

Re: Sargon 1978 UCI Available

Posted: Fri Jun 05, 2020 2:07 pm
by ThatsIt
Hi !

I've started a test for our 40/4 + ... ratinglist.

https://cegt.forumieren.com/t1308-testi ... 8-1-00-uci

Best wishes,
G.S.
(CEGT team)

Re: Sargon 1978 UCI Available

Posted: Fri Jun 05, 2020 5:10 pm
by Gabor Szots
ThatsIt wrote: Fri Jun 05, 2020 2:07 pm Hi !

I've started a test for our 40/4 + ... ratinglist.

https://cegt.forumieren.com/t1308-testi ... 8-1-00-uci

Best wishes,
G.S.
(CEGT team)
I'm looking forward to your results, Gerhard. I have found it a bit weaker than expected, maybe around 1300 on our scale.

Regards,
Gabor

Re: Sargon 1978 UCI Available

Posted: Fri Jun 05, 2020 5:43 pm
by Werewolf
So much fun. I really hope Sargon V gets ported to UCI.


Sadly it looks like their final work - Kasparov SPARC - won't make it into Franz's collection

Re: Sargon 1978 UCI Available

Posted: Fri Jun 05, 2020 6:22 pm
by mephisto
Thanks Bill

I am able to play against Sargon on my full size Certabo electronic chess board and am really impressed. I remember years ago ordering the Sargon book from my local library to look at the code.

Would be nice if someone could port Sargon to be used with the Android chess apps.

Re: Sargon 1978 UCI Available

Posted: Fri Oct 16, 2020 11:35 pm
by lkaufman
Have any rated human players played games against Sargon on a modern computer to provide any data on the human rating it might earn today? If so at what time control?

Re: Sargon 1978 UCI Available

Posted: Sat Oct 17, 2020 12:09 am
by AdminX
lkaufman wrote: Fri Oct 16, 2020 11:35 pm Have any rated human players played games against Sargon on a modern computer to provide any data on the human rating it might earn today? If so at what time control?
Because this is releate (Messchess).

Code: Select all

AVE Micro Systems
 =================                                                    Freq. ROM   RAM
 Module       Year  Chess computer                           Bit  CPU  MHz   kB    kB  Program author    Elo
-------------------------------------------------------------------------------------------------------------
^arb          1980  ARB Sargon 2.5                            8  6502    2    8     2  D&K. Spracklen   1370
^arbgms       1980  ARB Sargon 4.0 Grand Master Series        8  6502    2   20     2  D&K. Spracklen   1705
^arbv2        2012  ARB V2 Sargon 4.0                         8  6502   16   20    32  D&K. Spracklen   1940

Re: Sargon 1978 UCI Available

Posted: Sat Oct 17, 2020 12:59 am
by Laskos
lkaufman wrote: Fri Oct 16, 2020 11:35 pm Have any rated human players played games against Sargon on a modern computer to provide any data on the human rating it might earn today? If so at what time control?

Maybe that helps:

http://talkchess.com/forum3/viewtopic.p ... 1&start=12

Re: Sargon 1978 UCI Available

Posted: Sat Oct 17, 2020 1:32 am
by lkaufman
Laskos wrote: Sat Oct 17, 2020 12:59 am
lkaufman wrote: Fri Oct 16, 2020 11:35 pm Have any rated human players played games against Sargon on a modern computer to provide any data on the human rating it might earn today? If so at what time control?

Maybe that helps:

http://talkchess.com/forum3/viewtopic.p ... 1&start=12
OK, as best as I can figure out from all the posts, the elo rating of Sargon 1 in 1978 was about 1400, and its estimated elo vs. humans on an i7 now is around 1700. The hardware speedup is either 50 to 1 or 6000+ to 1 depending on which post you believe; if it is 50 to 1 this all makes sense, since 1700 elo is not too far out of line with 1254 CCRL Blitz if you contract rating differences by a third or so. I get 52knps on my very fast i7 which means about 40k on a typical one, so if there is some evidence that the original hardware got around 800 nps then everything fits. The 6000 to 1 figure is hard to credit, especially since it referred to using some old hardware, not an i7, so an i7 might be 10000 to 1 which means the original Sargon got 4 nodes per second?? That seems impossibly low.
I note that the 1700 elo mentioned was based on Shredder and SF versions set to 1600, but does anyone know whether those ratings were themselves based on human games or on games with CCRL rated engines?

Re: Sargon 1978 UCI Available

Posted: Sat Oct 17, 2020 1:47 am
by mwyoung
lkaufman wrote: Sat Oct 17, 2020 1:32 am
Laskos wrote: Sat Oct 17, 2020 12:59 am
lkaufman wrote: Fri Oct 16, 2020 11:35 pm Have any rated human players played games against Sargon on a modern computer to provide any data on the human rating it might earn today? If so at what time control?

Maybe that helps:

http://talkchess.com/forum3/viewtopic.p ... 1&start=12
OK, as best as I can figure out from all the posts, the elo rating of Sargon 1 in 1978 was about 1400, and its estimated elo vs. humans on an i7 now is around 1700. The hardware speedup is either 50 to 1 or 6000+ to 1 depending on which post you believe; if it is 50 to 1 this all makes sense, since 1700 elo is not too far out of line with 1254 CCRL Blitz if you contract rating differences by a third or so. I get 52knps on my very fast i7 which means about 40k on a typical one, so if there is some evidence that the original hardware got around 800 nps then everything fits. The 6000 to 1 figure is hard to credit, especially since it referred to using some old hardware, not an i7, so an i7 might be 10000 to 1 which means the original Sargon got 4 nodes per second?? That seems impossibly low.
I note that the 1700 elo mentioned was based on Shredder and SF versions set to 1600, but does anyone know whether those ratings were themselves based on human games or on games with CCRL rated engines?
You can estimate the speed up. The level times 1ply meaning level 1, 2 to 2..... level 6 for 6 ply took an average of 4 hours. Sargon did not have time controls only levels. Take a few positions and see how long your Sargon takes to search 6 ply. And compare that to 4 hours.This will give you a speed ratio compared to a TRS-80 computer.