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Subject: Re: Ponder=off is in my opinion better on single system and about tb's!

Author: Frank Quisinsky

Date: 07:50:47 07/29/01

Go up one level in this thread


On July 28, 2001 at 10:59:36, Robert Hyatt wrote:

>On July 28, 2001 at 04:17:18, Uri Blass wrote:
>
>>On July 28, 2001 at 01:12:41, Terry McCracken wrote:
>>
>>>On July 27, 2001 at 18:58:30, Dann Corbit wrote:
>>>
>>>>On July 27, 2001 at 18:44:45, Roy Eassa wrote:
>>>>
>>>>>On July 27, 2001 at 16:55:55, Dann Corbit wrote:
>>>>>
>>>>>>On July 27, 2001 at 16:51:08, Roy Eassa wrote:
>>>>>>
>>>>>>>Be careful, Dann.  Dr. Hyatt has argued strongly that ponder should always be
>>>>>>>on, even with a single CPU.  (It seemed counter-intuitive to me too, but you
>>>>>>>should check out his recent postings -- over the past couple days, I think.)
>>>>>>
>>>>>>Not when both engines play on the same machine.
>>>
>>>
>>>>>>No way.
>>>>>
>>>>>
>>>>>Yes way!  I reacted the same way (in my head), but I respect Dr. Hyatt and his
>>>>>arguments are worth reading at least!
>>>>
>>>>If you run two engines which are both pondering on a single CPU machine, then
>>>>you are simply out of your mind.
>>>>
>>>>I think you must have misread the arguments.
>>>
>>>No Dan he's read the arguements correctly!
>>>
>>>Posted by Robert Hyatt (Profile) on July 27, 2001 at 13:28:16:
>>>
>>>In Reply to: Re: Permanent Brain ON vs Permanent Brain OFF posted by Uri Blass
>>>on July 27, 2001 at 11:58:57:
>>>
>>>
>>>On July 27, 2001 at 11:58:57, Uri Blass wrote:
>>>
>>>>On July 27, 2001 at 11:18:08, Miguel A. Ballicora wrote:
>>>>
>>>>>On July 26, 2001 at 14:41:54, Robert Hyatt wrote:
>>>>>
>>>>>>On July 26, 2001 at 12:55:06, Miguel A. Ballicora wrote:
>>>>>>
>>>>>>>On July 26, 2001 at 10:43:45, Robert Hyatt wrote:
>>>>>>>
>>>>>>>>On July 26, 2001 at 09:56:24, Matthias Gemuh wrote:
>>>>>>>>
>>>>>>>>>
>>>>>>>>>Hi Robert,
>>>>>>>>>
>>>>>>>>>I think you just wanted to make a joke. We all know that PONDER OFF hurts nobody
>>>>>>>>>(Fritz used its full time). PONDER ON on one CPU is very appropriate to arrive
>>>>>>>>>at wrong engine comparasons.
>>>>>>>>>
>>>>>>>>>Regards,
>>>>>>>>>Matthias.
>>>>>>>>
>>>>>>>>
>>>>>>>>>>>>>both will get 1/2 of the machine and the time controls won't be screwed up.
>>>>>>>>
>>>>>>>>ponder=off exposes the opportunity for a program to get into time trouble
>>>>>>>>because it assumes it will save time with ponder=on when it really can't since
>>>>>>>>it is disabled...
>>>>>>>
>>>>>>>Why the program should assume that it will save time in with ponder=on when
>>>>>>>it knows that it is off already?
>>>>>>>Shouldn't a program take this into account?
>>>>>>>If ponder=off is an option for the program, it should notice the difference
>>>>>>>and act accordingly IMHO.
>>>>>>>
>>>>>>>Regards,
>>>>>>
>>>>>>
>>>>>>because in my case, 99.9% of all games played have ponder=on.  I only disable
>>>>>>pondering to debug so that I can reproduce the same searches over and over
>>>>>>when necessary.  Since almost all real games are played with ponder=on, I don't
>>>>>>have a special time-allocation formula for ponder=on and another one for
>>>>>>ponder=off.  I just have one that _assumes_ ponder=on.
>>>>>>
>>>>>>I see no reason to waste what little time I have working on something that is
>>>>>>hardly going to be used...
>>>>>
>>>>>Well, it is used a lot actually by lots of people already. Most of the people
>>>>>are running matches with ponder=off for some reasons.
>>>>>If both engines were tuned for ponder=off, it will be the best condition to
>>>>>optimze the resources since time used pondering is never as good a time used
>>>>>thinking. For instance, you have a competitive mindset in your answer but if my
>>>>>purpose is to run a match between engines to learn a particulat opening, I want
>>>>>my resources to be used as efficient as possible. That is ponder=off for both.
>>>>>Maybe you could consider making Crafty to be able to process "ponder=off"
>>>>>accordingly because there will be users that would benefit from it.
>>>>>
>>>>>Regards,
>>>>>Miguel
>>>>
>>>>Crafty is not a commercial program so I guess that the way that users use it is
>>>>not important for Bob.
>>>>
>>>>I also do not think that the difference between ponder on and ponder off is more
>>>>than 20 elo in most of the practical cases.
>>>>
>>>>Uri
>>>
>>>
>>>I disagree.   When this first cropped up a couple of years ago, I ran a test,
>>>gnuchess on a single-cpu, vs crafty on a quad pentium-pro 200, but using only
>>>one cpu.  The quad was far slower than the 500mhz single cpu by a significant
>>>amount.  The match was pretty even (ponder=on) even though crafty had a much
>>>slower processor.  With ponder=off, the match was way more lop-sided in favor
>>>of GNU because crafty would get into time trouble and near the end of the
>>>time period it would have to move too quickly to avoid losing on time.
>>>
>>>It was _clearly_ worse.  And by more like 100 points, too.  I adjusted it a bit
>>>to help, but I have _never_ invested as much time in the ponder=off timing as
>>>I have in the ponder=on timing.  And I never will, any more than I am going to
>>>try to tune my son's mustang to run on a road coarse when we only take it to
>>>the 1/8th and 1/4th mile drag strips...
>>>
>>>I think you should spend the time making it optimal in the way it will normally
>>>be used, not in oddball configurations...
>>>
>>>
>>>I ran a bunch of games, everything equal but the hardwar
>>>
>>>
>>>Quote/Hyatt; Nope... no joke at all.  Two programs, one machine, my preference
>>>is ponder=on.
>>
>>Note that it is hyatt's opinion.
>>I said that in most of the practical cases the difference between ponder on and
>>ponder off is not more than 20 elo.
>>
>>The practical cases are usually with the commercial programs.
>>I am not talking about amatuers like GNUchess.
>>
>>I agree that there may be a big difference with amatuers.
>>One reason is simply the fact that part of the amatuers do not know to ponder so
>>ponder off is clearly better for them than ponder on.
>>
>>I do not know if this was the reason for GNU chess but when I read 100 elo
>>difference I suspect that this is the reason.
>>
>>I do not believe that program are handicapped by more than 100 elo if they do
>>not know to ponder.
>>
>>I believe that the difference is even less than 70 elo(70 elo is the difference
>>from doubling the speed of the program and it is better to be twice faster and
>>play without pondering).
>>
>>Uri
>
>
>No...  the problem was definitely in crafty.  I was playing games of 15 minutes
>for 40 moves.  At move 35-40, crafty was in time trouble and made bad moves in
>many (but not all) games because it had far less time than GNU did.  You can't
>afford to do a 6-8 ply search and move when your opponent is doing 10-12 plies
>on that same move because he has used his time more reasonably.
>
>I fixed the problem in a simplistic way by simply spreading out the time over
>the time-control-moves in a more uniform way.  Very unlike the way a human plays
>chess of course, but it was one quick-and-dirty way to avoid getting blasted
>near the end of the time control.

Hi Bob,

the same discuss then for 2 years here :-)

I, the ex non ponderer, will say the following:

01.
You have right if you say that with ponder = off engines have time manangment
problems, not all and not in all games but it's an important point. I know that
this is for statistics not sooo important (ELO statistic).

02.
Match without ponder on single system with Athlon 1Ghz:
Engine A = 1Ghz
Engine B = 1Ghz

Match with ponder on a single system with Athlon 1Ghz:
Engine A = ~ 497-500Mhz
Engine B = ~ 497-500Mhz

Now we have 25-40% ponder hits if the engines play on the same level (after my
experiments).

Result:
500Mhz + 25-40% ponder hits = ~700MHz.

With ponder = on, the matches are running with 700Mhz on 1Ghz Athlon!
With ponder = off, the matches are running with 1Ghz on 1Ghz Athlon!

I believe better is to play with ponder = off on single system. OK, the time
managment is a good point so say please with ponder but 300 MHz is a better
point to say please without ponder.

03.
4-piece and 5-piece tablebases and engine-engine matches on a Dual system ...

This is not very clear.
We have engines witch used tablebases very aggressive or not very aggressive.

Example:
Gromit - Patzer with 5-pieces ...

Gromit played move 50 in 2:45 with ponder = on and 5-pieces.
Only 20-30% processor time in this game if Gromit used 5-pieces.
Patzer played move 50 in 1.25 with ponder = on and 5-pieces.

Now the same positions with 4-pieces ...

Gromit play move 50 in 1.58! with ponder = on and *4-pieces*.
Patzer played move 50 in 1.13 with ponder = on and *4-pieces*.

Without 4-piece tablesbases are the differents not very important.

In my opinion it is better to play eng-eng matches with ponder on a dual system
with 4-piece tablebases.

Best
Frank



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