Author: José Carlos
Date: 07:54:23 02/06/04
Go up one level in this thread
On February 06, 2004 at 10:41:21, Vasik Rajlich wrote: >On February 06, 2004 at 10:27:48, José Carlos wrote: > >>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 >> >> Why not? Move WAC positions down inside the search tree instead of thinking of >>them only as root positions. Solving them quickly at the root means seing the in >>advance in longer time controls. >> >> José C. > >The stakes are much higher at the root. Overlook a possible tactic at the root, >or play a move (at the root) which walks into a tactic, and you just cost >yourself somewhere around half a point. No improvement in positional play will >make up for that. Overlook a tactic four moves in which makes it possible to >play some good positional move and you cost yourself maybe 1/200th of a point. > >It's a question if you accept that some extensions/reductions are good for >tactics and bad for positional play. > >Vas My answer was directed to: >>>If you are playing at 40 / 2 on a quad opteron, do you care how many WAC >>>positions you can solve in 1 second? To answer you: a certain root position was a leaf node some moves before. Tactics are importante everywhere in the tree. The 1/200th thing I don't understand what you mean. José C.
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