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Subject: Re: Question for Hyatt about Alpha/Beta

Author: Uri Blass

Date: 06:51:50 02/06/04

Go up one level in this thread


On February 06, 2004 at 09:07:17, Anthony Cozzie wrote:

>On February 06, 2004 at 06:26:20, Uri Blass wrote:
>
>>On February 06, 2004 at 05:54:29, Vasik Rajlich wrote:
>>
>>>On February 06, 2004 at 03:42:42, Uri Blass wrote:
>>>
>>>>On February 06, 2004 at 02:15:35, Tord Romstad wrote:
>>>>
>>>>>On February 05, 2004 at 15:15:47, Uri Blass wrote:
>>>>>
>>>>>>I think that you underestimate your engine.
>>>>>>It seems to get similiar depth to crafty.
>>>>>>
>>>>>>For example in the following position it got depth 11 even in blitz 4+2
>>>>>
>>>>>Yes, 11 plies in blitz games is not unusual.  But 11 plies in Gothmog and 11
>>>>>plies in Crafty is not the same.  I do much more forward pruning and depth
>>>>>reductions than Bob, and fewer extensions.  In non-tactical positions like
>>>>>the one you give, my qsearch is also considerably smaller than Bob's (I think).
>>>>>
>>>>>Tord
>>>>
>>>>I do not think that there is a big difference.
>>>>Crafty searches bigger tree because it searches more irrelevant lines.
>>>>
>>>>I guess that the main advantage of Crafty relative to Gothmog when you use one
>>>>processor is superior evaluation(Gothmog's evaluation is more complex but bigger
>>>>is not always better and not having  bugs or some too optimistic scores of
>>>>gothmog that lead to wrong sacrifices can be more important and it is possible
>>>>that Gothmog can get crafty level if you only reduce the big positional scores
>>>>that encourage it to sacrifice).
>>>>
>>>>I do not think that gothmog see less than crafty in the relevant lines(crafty
>>>>has bigger tree but it proves nothing).
>>>>I know that test suites are no proof but results of the gcp test suite give me
>>>>the impression that cases when Gothmog can see more than crafty are not rare.
>>>>
>>>>Uri
>>>
>>>I have the theory that the greater your search resources (ie combination of time
>>>and hardware), the less important is the search, and the more important is the
>>>evaluation.
>>
>>I do not agree with that theory.
>>
>>For example suppose a program has no tablebases.
>>
>>With deep search it may not need knowledge how to win KQ vs K when with small
>>search it may need the knowledge.
>>
>>If the hardware is fast enough the program can solve the game with only piece
>>square table evaluation.
>>
>>Of course we are not going to see it but with good hardware evaluation what win
>>is better in some endgames become unimportant because the program will not fail
>>to win thanks to search.
>>
>>Uri
>
>Vas's point is this (and its the same reason Zappa is a relatively weak engine
>tactically):
>
>If you are playing at 40 / 2 on a quad opteron, do you care how many WAC
>positions you can solve in 1 second?
>
>anthony

WAC is test suite only to test for not having obvious bugs.
It is not a serious test suite to use to evaluate tactical strength.

I am more interested in how many positions I solve in test suites like ecm-gcp
or arasan test suite.


For arasan3 I got for example the table in the bottom of this post for my cct
version when I gave it to search 10 minutes per position.

I want to improve in all time controls and there are changes that can help me in
all time controls.

Uri

Results:

<=Sec Solved Total  PosNr
----- ------ ------ -----------------------------------------------------------
    1      7      7 19 24 27 31 36 50 51
    2      1      8  7
    3      1      9 38
    4      1     10  3
    6      2     12  8 46
    7      3     15 17 26 28
    8      3     18 32 53 57
    9      1     19  6
   10      2     21  2 48
   11      1     22 23
   18      1     23 42
   20      1     24 16
   24      1     25  4
   25      1     26 58
   40      1     27 49
   54      1     28 20
   67      1     29 40
   69      1     30 10
   71      1     31 34
  115      1     32 41
  152      1     33 55
  162      1     34 14
  166      1     35  1
  193      1     36 22
  290      1     37 47
  374      1     38 33
  402      1     39 12
  456      1     40 11
  559      1     41 39
Failure              5  9 13 15 18 21 25 29 30 35 37 43 44 45 52 54 56

41 problems solved.
17 problems unsolved.







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