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Subject: Re: Okay. You are right :-)) NT

Author: Eran

Date: 05:15:48 02/08/02

Go up one level in this thread


On February 08, 2002 at 02:11:17, Uri Blass wrote:

>On February 08, 2002 at 02:07:31, Uri Blass wrote:
>
>>On February 07, 2002 at 11:25:17, Eran wrote:
>>
>>>On February 07, 2002 at 08:30:07, Uri Blass wrote:
>>>
>>>>On February 06, 2002 at 19:48:13, Eran wrote:
>>>>
>>>>>
>>>>>The interesting comparative results of the MATS test set (The MAstricht Test
>>>>>Set) are shown below.
>>>>>
>>>>>Fritz7 with futility pruning (selected):
>>>>>Result 18 out of 24 = 75%  Average time = 18.05s / 163.09s
>>>>>
>>>>>Fritz7 without futility pruning (deselected):
>>>>>Result 19 out of 24 = 79%  Average time = 25.08s / 145.04s
>>>>>
>>>>>Fritz7 with latest update (version 7.0.0.6 - January 22, 2002)
>>>>>MATS test set contains 24 positions in total
>>>>>
>>>>>For more information about MATS test set, please click below
>>>>>
>>>>>http://www.cs.rulimburg.nl/~uiterwyk/icca/mats.htm .
>>>>>
>>>>>Also, the test set in epd format can be downloaded from there.
>>>>>
>>>>>I tried to compare how well Fritz7 played with and without futility pruning.
>>>>>Please see the comments as follows below.
>>>>>
>>>>>Firstly, based on the test Fritz7 without futility pruning seemed to solve more
>>>>>positions than with futility pruning. The only game number 10 in the test set
>>>>>was solved by Fritz7 without futility pruning only. The rest were the same but
>>>>>with futility pruning Fritz7 searched a bit faster. That indicated that without
>>>>>futility pruning Fritz7 seemed to play better in positional games. Obviously,
>>>>>with futility pruning Fritz7 overlooked it because futility pruning was an
>>>>>aggressive, faster and deeper search that might miss some good moves. Secondly,
>>>>>Fritz7 without futility pruning seemed to search slower than with futility
>>>>>pruning but overlooked less.
>>>>>
>>>>>Conclusion: I believe that Fritz7 with futility pruning is better in
>>>>>time-control games in tournament such as rapid chess, sudden death and any
>>>>>tactical-oriented games. On the other hand, if you want to let Fritz7 analyze a
>>>>>position or a game for a long time, futility pruning should be turned off since
>>>>>time is not very important.
>>>>
>>>>I suspect that you did not give Fritz enough time in order to know what happens
>>>>at long time control.
>>>>I think that it may be more interesting to see results of Fritz at 1 hour per
>>>>move with and without futility pruning.
>>>>
>>>>total 48 hours for all the test
>>>>average time of 20 seconds per position means that there was no position when
>>>>Fritz needs more than 10 minutes to solve.
>>>>
>>>>I do not believe that there is no position when Fritz needs more than 10 minutes
>>>>to solve and I guess that if you give Fritz one hour per move you will find more
>>>>information.
>>>>
>>>>I tend to believe that the default option is best for all time control unless I
>>>>see a proof that it is not and the results are not enough to convince me.
>>>>
>>>>Uri
>>>
>>>If the futility pruning cuts one variation that leads to finding the best move
>>>1.b4 in the game # 10 in the MATS test set, then Fritz7 will never search that
>>>variation again because it is cut forever. So I don't believe that if Fritz7
>>>with futility pruning continues searching, it will ever find the best move 1.b4
>>>in one or two hours later. I do not think that a very long time calculation for
>>>Fritz with futility pruning makes sense.
>>
>>
>>You are clearly wrong in your assumption
>>
>>For analysis of Fritz7 with futility pruning see
>>http://www.icdchess.com/forums/1/message.shtml?212445
>>
>>Fritz7 needs more than an hour but it finds b4
>>
>>Uri
>
>I see that Fritz7 analyzed the position twice in 2 different computers.
>In both cases it found b4 at depth 19.
>
>Futility pruning can help the program to be faster or slower in finding moves
>but it is not selective search that prevent the program to see moves forever.
>
>Uri



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