Author: Vasik Rajlich
Date: 07:41:21 02/06/04
Go up one level in this thread
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
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