Author: leonid
Date: 11:28:12 10/03/01
Go up one level in this thread
On October 03, 2001 at 12:08:07, Paul wrote: >On October 02, 2001 at 23:04:12, leonid wrote: > >>On October 02, 2001 at 22:02:56, Paul wrote: >> >>>On October 02, 2001 at 20:00:24, leonid wrote: >>> >>>>On October 02, 2001 at 10:07:56, Paul wrote: >>>> >>>>>On October 01, 2001 at 12:56:43, leonid wrote: >>>>> >>>>>>Hello! >>>>>> >>>>>>Today I wanted to put some simple mate position. This one, at least, have very >>>>>>unsophisticated shape. >>>>>> >>>>>>[D]8/8/3QQQQK/3nbrpn/3pQQBQ/3bQrqq/3qRqNB/3qRnNk w - - >>>>>> >>>>>>Please indicate your result. >>>>>> >>>>>>If you happened to have some version of Chess Master that do brute force search, >>>>>>please find for me time that it take for him to find mate in 4 and 5 moves for >>>>>>this position. I need this in order to have some idea what is his branching >>>>>>factor. I tried to do this myself with CM5000, that I have, but found no >>>>>>possibility to indicate my position. Since CM is the most performant and the >>>>>>most frequently mentioned program that solve the mate, I would like to know his >>>>>>basic mate solving capability. >>>>>> >>>>>>Thanks, >>>>>>Leonid. >>>>> >>>>>Hi! >>>> >>>>Hi! >>>> >>>>>Haven't got CM6000 installed at the moment, and don't remember if it's got a >>>>>mate level search, but John Merlino is the best person to answer that. >>>>> >>>>>For Pretz this is a difficult problem, for now it finds this: >>>>> >>>>>06:18 WM9 11 Nxh3 Ndxf6 Bxf3 Ng4+ Qfxg4 Bg7+ Qxg7 Rf6+ Qgxf6 Bxe4 Nxf2+ Qxf2 >>>>>Nf4+ Bxf3 Qgxf3+ Qxf3 Qxf3# >>>>>20:52 WM8 11 Bxf3 Ndxf6 Bxg3 Ng4+ Qfxg4 Bg7+ Qxg7 Rf6+ Qgxf6 Nh2 Nf4+ Nxf3 >>>>>Qgxh3+ Qh2 Qxh2# >>>> >>>>I am not sure what you found but mine looked only by selective. I don't know >>>>what is the minimal number of moves for this position. Mate by selective was >>>>found 10 move deep. It took pretty long time - 66 seconds. >>> >>>Oh ... I didn't realize you couldn't read my output format, I'll explain: >>> >>><minutes:seconds> <evaluation> <ply> <principal variation> >>> 06:18 WM9 11 Nxh3 Ndxf6 Bxf3 Ng4+ Qfxg4 ... Qxf3# >>> 20:52 WM8 11 Bxf3 Ndxf6 Bxg3 Ng4+ Qfxg4 ... Qxh2# >> >>It is good that you explained. I was lost in 'W', 'M' and only after your >>indication could find what it is. >> >> >>>The evaluation 'WM9' means 'W'hite 'M'ates in '9' moves, and WM8 ... you got it! >>>So Pretz first found a mate in 9, and after that on the same ply a mate in 8. >>> >>>I checked later today without hash, just to be sure, and I think the mate in 8 >>>is correct. Also tried some different settings that made everything quite a bit >>>faster (just over 2 minutes for the mate in 9), but found nothing shorter than a >> >>For this position I actually went only 6 moves deep that took already 13 min. >>Branching factor was 13 and look like that it have tendency to diminish. Between >>four and five moves it was almost 16. My guess is that if the mate is there in 8 >>moves then it could take around 3 hours to reach first solution. For now I am >>not that sure what to do first, look seven moves deep, or go directly 8 moves >>for mate. >> >>>mate in 8. >>> >>>Maybe you can check with LLChess's brute force search? I started our Champion! >>>solver Chest on this problem a few minutes ago, but don't see a way to set the >>>size of the hash table(s) yet. The documentation mentions an -M switch, but >>>Chest doesn't seem to accept that in a DOS box under XP. >> >>It is good that you, at least, can use it. I am not at all knowledgeable of all >>abreviations and expressions that are in its manual. So for me the best strategy >>for now is to wait for Chest future edition. Then it will be easy for me to >>recognize all his strange expressions by looking stright into his graphics >>interface. > >Chest reported this: > >8/8/3QQQQK/3nbrpn/3pQQBQ/3bQrqq/3qRqNB/3qRnNk w - - > acn 807241484; acs 6185; bm Bxf3 Bxg3 Nxh3 Qfxf3 Qxf2; ce 32752; dm 8; > id "leonid 1/10/01"; > pv Nxh3 Nhxf6 Bxg3 Ng8+ Qexg8 Bg7+ Q8xg7 gxh4 Qxf2 Rh5+ Qxh5 Qxf4+ Ngxf4 hxg3 >Ng5#; > >So I guess there are 5 possible key moves to a mate in 8! Nice to see Chest in >action on my pc for the first time. Very practical as well. I left this position for night 8 moves deep. Even after 8 hours response was not there. It could be that after 6 move my branching factor jumped once again. Cheers, Leonid. >Groetjes, >Paul > >>>Hmmmm ... Heiner, hope you read this? It's now taking about 42MB of memory ... >>>started it like this: 'chest319 -b -Z8 x.epd'. Also tried -M350, but to no >>>avail. >>> >>>Oh ... and I did not find a mate for black in this position, and neither did >>>Pretz. :)
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