Author: Uri Blass
Date: 07:50:29 09/03/04
Go up one level in this thread
On September 03, 2004 at 10:29:11, Stuart Cracraft wrote: >On September 03, 2004 at 03:15:07, Uri Blass wrote: > >>On September 03, 2004 at 00:43:27, Stuart Cracraft wrote: >> >>>So today I find out that my recapture is bad. It must be. Bob said so. >>> >>>I take 1 minute to reimplement it to be "extend on 2nd capture on the same >>>square in a row" because I heard someone else talking about that's the >>>way they do it and got a surprise a minute after that. >>> >>>The result is that Qxf4 for Win-at-Chess comes into view >>>in 98 seconds and holds after having been missed after seemingly >>>endless runtime with the old bad recapture in or out. >> Of course >>>it is nothing like the 13,000 nodes that Tord (was it?) solves >>>141 in. Perhaps we should have a contest for who solves 141 in >>>the fewest moves. >> >>I see no point for it. >> >>I am sure that I can solve Qxf4 even in less nodes than tord by adding some >>stupid extensions but this is not the target and the target is to play better. >> >>I discovered that I can solve more positions in the ecmgcp if I reduce my >>evaluation based pruning but again it is not the target and the main question is >>if I can play better with it. >> >> He would surely win. It takes me 24 million. >>>I admire a search that is so directed in so few nodes. Surely >>>we pay homage to Berliner with it, eh? Retire in peace in Florida >>>and then two category 4 storms hit. Unlucky fellow. >>> >>>Alpha=-1182 Beta=-682 Maxdepth=9999999 MaxTime=100000 >>> 1/13 g2f1 0.01 -953 945 g2f1 f4d5 >>> 2/13 g2f1 0.01 -953 1535 g2f1 f4d5 c1g5 >>> 3/15 g2f1 0.02 -953 5010 g2f1 f4d5 c1g5 d5f6 >>> 4/23 g2f1 0.09 -953 21387 g2f1 f4d5 b3d5 c6d5 c1c7 d6c7 f1g1 >>> 5/25 g2f1 0.65 -953 179404 g2f1 b5b4 b3a4 f4d5 f6g5 d5e7 >>> 6/44 g2f1 3.15 -953 728459 g2f1 b5b4 b3a4 f4d5 f6g5 d5e7 >>> 7/48> g2f1 64.75 -703 15048349 g2f1 e8c8 f1g1 c8e8 c1b1 f4e2 g1g2 e2d4 >>> 7/48 c1f4 98.86 5113 24322991 c1f4 e8e6 f4g5 d7e7 b3e6 e7e6 h1d1 d6e7 >>> 8/48< c1f4 98.88 4863 24327933 c1f4 e8e6 f4g5 d7e7 b3e6 e7e6 h1d1 d6e7 >>> 8/48 c1f4 108.60 4863 26455348 c1f4 e8e6 f4g5 d7e7 b3e6 e7e6 h1d1 d6e7 >>> 9/48> c1f4 159.87 5113 38207334 c1f4 e8e6 f4g5 d7e7 b3e6 e7e6 h1d1 d6e7 >>> >>>I know my PV is screwy and wonder why Bxf4 isn't played next. Anyone >>>know why? To me, Qxf4 followed by Bxf4 and then rook taking along the >>>H file looks like the natural PV. I wonder if that is another nasty >>>bug lurking. >> >>No >> >>After Qxf4 Bxf4 lead to a sinple mate so black has no choice but not to capture. >> >>If you extend Bxf4 then it is clear than not playing Bxf4 is not extended so >>even if both Bxf4 and the alternative are equal you are going to see that Bxf4 >>is losing by mate earlier because of extensions. >> >> I am surprised there can be so many remaining considering >>>a fairly decent run-of-the-mill score on WAC 1-300. The set seems to >>>have shortcomings. Good for a first year's development effort though. >>> >>>I am not able to speed 141 up yet with Moreland's Mate Threat Null extension >> >>If you are not able to see it at smaller ply with mate threat extension then you >>must have a bug and I suspect that you have return beta or return alpha and not >>return val in your search(otherwise even without checks in the qsearch you could >>see Qxf4 Bxf4 Rxh5 null Rh8#). > >I am glad you raised this as I wanted to talk about. My program is a mixture >of return(value), return(beta), and return(alpha) and I've not been happy with >that. My quiescence is mostly return(beta). The main search is a mixture. >Whenever I make everything return(value), PVS goes weird on me and stops >solving problems as well (big drop). What should I do? I think that you may try only return value in case that value is mate or -mate score like Tord suggested. I think that the qsearch is the important part that return value can help. I see no logical point in having return value in the main search when you do not have return value in the qsearch. Uri
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