Author: Robert Hyatt
Date: 06:43:33 05/07/01
Go up one level in this thread
On May 07, 2001 at 03:19:05, Uri Blass wrote: >On May 06, 2001 at 23:53:59, Robert Hyatt wrote: > >>On May 06, 2001 at 19:46:43, Vincent Diepeveen wrote: >> >>>On May 06, 2001 at 02:28:14, Uri Blass wrote: >>> >>>>I gave Deep Fritz to analyze similiar number of nodes to Deeper blue and Deep >>>>Fritz seems to be clearly better in tactics. >>>> >>>>Deep Fritz needs only 191728 knodes to see the line Rf5+ Ke3 >>>>It means only 1 second if I asuume 200,000,000 nodes per second. >>>> >>>>I believe that Rf5+ failed low at depth 17 for Deeper blue for the reason Ke3. >>>>The pv of deeper blue at smaller depthes is Rf5+ Ke2 >>> >>>11 ply for those who are good in math and a bit more real to the world. >> >>Uri is correct. Unless you _still_ dispute the direct statement(s) by the >>Deep Blue team. >> >> >> >>> >>>>Deep Fritz probably does better extensions than Deeper blue because Deep Fritz >>>>see big fail low at depth 16. >>> >>>Fritz hardly has dangerous extensions. >>> >>>Diep has. note i am not extending passers much. Just a bit and only >>>now and then. >>> >>>The Big fail low comes at 12 ply for DIEP. Then it sees Rf5 is losing >>>because of Ke3 though it initially wants to go e3. Then i did a state >>>check to see what the deepest search lines are. You can see it >>>yourself: >> >> >>What does any of this matter? Their score was bad... yours is bad, black >>is lost... I don't see where you see it any faster than they did... > >I see that Deeper blue score is clearly better than the score of other programs >after search. > >Deeper blue said only 2.1 pawns for white after 73 seconds of search when other >programs has no problem to see clearly better score for white. You are making the same mistake _everyone_ makes. Taking scores to be an absolute assessment of the truth. IE try Vincent's scores. And compare them to mine. I have seen many games where we were different by 1-2 pawns, and more often than not mine has been right. It is _easy_ to cause this. I take the more practical approach of "+ is good for white, - is good for black" but I don't fall into the trap of +1.7 here is much better than 1.4 by that program. IE don't look for an eval to be an "absolute" evaluation of the position. To do so is a _big_ mistake. > >I can explain 1 pawn difference or even 1.5 pawns difference by different >evaluation but the difference between Crafty's evaluation(4.22) and their >evaluation(2.1 after 73 seconds) is more than 2 pawns(I mean to the evaluation >of Rf5+) and it can be explained only by the fact that crafty could see deeper. > It has nothing to do with depth most likely. It has to do with evaluation. Crafty is asymmetric. They were not. That most likely is _the_ reason for the difference. >Their score at depth 15 is only 1.63 for white so if you compare same depth then >it is clear that Crafty did better extensions than deeper blue. You are diagnosing the disease without _ever_ seeing the patient. _any_ doctor will tell you that is an unforgivable sin that leads to dire consequences. > >If you do not like depth 15 of move 43 because of the bug that cause deeper blue >to play Rd1 you can take depth 11(6)=17 at move 42 abd you find there a score of >only 1.36 pawns for white. > >I assume that 11(6) means depth 17 with futility pruning and in this case the >top programs of today clearly do better extensions than deeper blue. > >Uri Based on what? You can _not_ see at _least_ the last 1/3 of their PV, or in the case of 11(6) the last 6 plies + the q-search.. so all you can use to make a conclusion is the absolute value of their score. Cray Blitz was _far_ more conservative in scoring than Crafty is. It would be quite common for Crafty to say +3 and Cray Blitz to say +1, with the _exact_ same PV. I don't see how you can conclude _anything_ with no data... I don't try to understand what they are seeing there since I (a) don't know what their positional eval terms are; (b) I can't see about 1/2 of their PV in most cases; (c) due to (b) I am stuck with (a). In short, trying to deduce some- thing from their output is nearly impossible.
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