Author: Geert van der Wulp
Date: 00:29:05 06/18/04
Go up one level in this thread
On June 16, 2004 at 18:56:41, Sune Fischer wrote: >On June 16, 2004 at 16:49:28, Steve Glanzfeld wrote: > >>On June 15, 2004 at 17:28:38, Vincent Diepeveen wrote: >> >>>On June 15, 2004 at 16:26:09, Steve Glanzfeld wrote: >>> >>>>No normal program will choose an unusual move (i.e. a queen sac) "out of the >>>>blue" in a normal position. Except, the program is completely broken. >>>> >>>>You guys are argueing as if it would be DOWNRIGHT BAD when a chess program finds >>>>good moves (quickly)... I wonder what a chess program looks like, when it is >>>>based on that philosophy :)) Does it try to avoid the good moves? So, if there's >>>>a lack of success, the chances are good that we have found a major reason here >>>>:) >> >>>"I created a version that was tactical brilliant. It solved *everything* in the >>>testsuites. Then i started playing with it and it was hundreds of points weaker >>>in games." Stefan Meyer Kahlen a few months ago. >> >>No engine can solve everything in every testsuite. There are not only tactical >>tests, for example (big surprise eh? :))) >> >>> >>>So the answer to your question is: The version that scores hundreds of points >>>more onto testsuites is NOT the version to play with at tournaments, because in >>>testsuites all those patzermoves work as we know and they do not in tournaments. >> >>Again, don't you understand that those moves HAVE WORKED in games? :) These are >>World Champion's winning moves! What are you talking about "do not work in >>tournaments"...??? >> >>Which program, in several versions, do you think ranks #2, #5 and #7 in the WM >>test results? Shredder! :)) Note, that the version ranking #2 has the same >>number of solutions as the leader. Ranks #1/3/6/8/9/10 are Fritz versions. Next >>best are CM versions, Hiarcs 9, and Deep Juniors. At the bottom of the list we >>find oldies and weaker freeware. >> >>So, we find the same engines in the top of that test's ranking list (from a >>total of 230 results in the currently available download), which we do as well >>find in many ranking lists based on games. >> >>I wonder why some people here have so much trouble understanding or accepting >>this. Strange. >> >>Steve > >I think it has been explained to you already, but I'll give it another try. > >The problem is that the implication >"higher testscores" => "stronger engine" is often false. > >There are severy reasons for that I think, some of them already mentioned. > >One of the biggest problems is that test positions are not really representative >of a real game. >It seems impossible to weigh in the different type of positions, ie. say you >have 10 king sac, 10 endgame and 10 midgame with subtle moves. Excuse me, a KING sac?? > >Now you take two engines and get resp. 4, 8, 2 and 6, 5, 3 solutions. > >The right kind of king sac can of course decide the game, but these position >may Yes, right, A KING sac ALWAYS decides the game. But are we testing the engines for helpmates or something? >occur rarely in games so it might not be hugely important for practical rating. It is true. In my own games I have never played a King sac myself, and I have never been astonished by one that my opponent played. >Of course the engine must also be able to get that kind of positions on the >board in the first place. Yes, true. I think most will not allow such King sac. > >The subtle midgame moves occur extremely frequently of course, but a few 0.1 >moves won't be enough to win a game. > >Being excelent in the endgame won't help much if you can never survive the >midgame. Etc.. > >So even though the two engines may score the same, it says absolutely nothing >about which will be the better player. > >Of course you can try and create a set of positions you think will be >representative and make a guess as to some proper weighing. >But that's all it's going to be, basicly guessing out of the blue. > >Even if one engine scores higher on all suites, there is still a chance it is >worse if e.g. it is much too "trigger happy" and generally overestimates its >chances in, say, passed pawn endgames. >A good example of that is wac2 I think, high passed pawn values will usually >help the engine find the right sac although the same "knowledge" can backfire in >other positions. > >-S. Geert
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