Author: Uri Blass
Date: 16:34:21 09/05/04
Go up one level in this thread
On September 05, 2004 at 19:14:30, Stuart Cracraft wrote: >On September 05, 2004 at 18:30:30, Bas Hamstra wrote: > >>On September 05, 2004 at 17:02:49, Uri Blass wrote: >> >>>On September 05, 2004 at 16:37:32, Stuart Cracraft wrote: >>> >>>>On September 05, 2004 at 15:58:39, Bas Hamstra wrote: >>>> >>>>>On September 05, 2004 at 14:56:14, Uri Blass wrote: >>>>> >>>>>>On September 05, 2004 at 14:30:01, Bas Hamstra wrote: >>>>>> >>>>>>>>My program has this in relation to checks, all conditionally compilable: >>>>>>>> >>>>>>>> 1) all checks-evasions in quiescence, unlimited occurrences >>>>>>>> 2) all checks-evasions in main search, unlimited occurrences >>>>>>>> 3) all checking-moves in quiescence, at the first ply of quiescence >>>>>>>> >>>>>>>>These are the three extensions. Only #1 and #2 have proved useful. >>>>>>> >>>>>>>Impossible. When I did 3) it solved wac141 within one second, using a mate >>>>>>>extension of a full ply. It takes 30.000 nodes and 6 plies to anounce M6. >>>>>> >>>>>>With mate extension of a full ply your search will explode because >>>>>>there are positions when there are a lot of checks and every reply to check is >>>>>>a mate threat. >>>>> >>>>>Not in my search. But I have taken actions to prevent "stapling" of useless >>>>>matethreats. I have done a full ply mate-extend in Tao 5.4 without problems. >>>>> >>>>>>6 plies to see the mate and only 30000 nodes. >>>>>>It seems to me hard to believe it espacially when I expect your search with >>>>>>full ply extension for mate to explode. >>>>> >>>>>See above for the explosion. I am not saying a full ply mate-ext is best, but I >>>>>have used it for years and it worked fine. This is probably also a matter of >>>>>what your qsearch can do. Mine can solve simple multi-move mates. >>>>> >>>>>>Of course checks in the qsearch helps but I still need 8 plies without mate >>>>>>extensions only to find the move without mate score(it is after I decided to >>>>>>reduce my evaluation based pruning). >>>>> >>>>>Yes, I checked and have the same result without mate-ext. >>>>> >>>>>>I will check with enabling mate extensions only in the first 11 plies(no need >>>>>>to extend after 11 plies to find mate in 6) and check results again. >>>>>> >>>>>>>Without it it has a hard time and it takes very long. The point is: if your >>>>>>>qsearch cannot find a simple mate in one (a capture only qsearch wont) chances >>>>>>>are you will find this mate a full 3 plies later than necessary. >>>>>>> >>>>>>>If you implemented 3) your program should mate-extend like crazy here... >>>>>>> >>>>>>>Bas. >>>>>> >>>>>>If he implements 3 then his program will crash because it will never get to the >>>>>>second ply of the qsearch because his qsearch call the main search and not the >>>>>>qsearch. >>>>> >>>>>You are right here. When you do checks on the first q-ply and call the mean >>>>>search for check-evasions, you will have unlimited checking sequences and that's >>>>>bad. >>>>> >>>>>Bas. >>>> >>>>Repetition detection would take care of that. >>>> >>>>My search terminates and never goes anywhere near the 99 maximum ply >>>>setting. Usually at 8, 9, 10, 11 ply it is no more than 4x the nominal >>>>main search depth, e.g. 32, 36, 40, 41 -- I don't limit quiescence to >>>>that, it just often turns out that way. >>>> >>>>No unlimited checking sequences noted due to repetition detection and >>>>draw return in both mainsearch and quiescence. >>>> >>>>On the other hand, I am anxious to try a quiescence that does not >>>>handoff to main search to get out of check in quiescence. I was hoping >>>>to do that this afternoon. >>>> >>>>Stuart >>> >>>I guess that you did not search the right positions or did not search deep >>>enough to get the 99 plies >>> >>>there are positions when there can be easily more than 99 plies of checks with >>>no repetition. >>> >>>Uri >> >> >>I have the same experience. >> >>Bas. > >Most programs I've heard of have a maximum ply setting beyond which the >search can't go. > >How about you Uri and you Bas? > >Stuart Movei assumes that the ply is always smaller than 100 If it is bigger than 100 the program may crash because it does not check if ply<100 in it's search. Practically based on my experience it never get close to 100. Uri
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