Author: Wayne Lowrance
Date: 07:24:20 09/23/99
Go up one level in this thread
On September 23, 1999 at 09:43:20, Robert Hyatt wrote: >On September 23, 1999 at 09:24:43, Wayne Lowrance wrote: > >>On September 22, 1999 at 22:54:07, Robert Hyatt wrote: >> >>>On September 22, 1999 at 20:25:56, Howard Exner wrote: >>> >>>>On September 22, 1999 at 13:42:26, Robert Hyatt wrote: >>>> >>>>>On September 22, 1999 at 13:40:37, Robert Hyatt wrote: >>>>> >>>>>>On September 22, 1999 at 11:46:29, Howard Exner wrote: >>>>>> >>>>>>>Do any of the programs with endgame tablebases solve this position? >>>>>>> >>>>>>>8/6Bp/6p1/2k1p3/4PPP1/1pb4P/8/2K5 b - - id Pos 111 - ECM98H.EPD; bm b3b2 >>>>>>> >>>>>>>It looks too difficult for non tablebase programs. >>>>>> >>>>>> >>>>>>Crafty solves it, but it takes longer than I would like to see... 11 minutes. >>>>>> >>>>>>here is the output: (quad xeon with all the 5 piece ending databases). >>>>>> >>>>>> 15-> 1:46 -0.09 1. ... Kd6 2. Bf8+ Ke6 3. f5+ Kf6 4. >>>>>> Kb1 Bd4 5. Ba3 h6 6. Bb2 h5 7. Bxd4 >>>>>> exd4 8. Kb2 hxg4 9. hxg4 d3 10. Kxb3 >>>>>> d2 11. Kc2 >>>>>> 16 2:21 -0.17 1. ... Kd6 2. Bf8+ Ke6 3. f5+ gxf5 >>>>>> 4. gxf5+ Kf6 5. Bc5 h5 6. Kb1 Kf7 7. >>>>>> Ba3 Kf6 8. Kc1 h4 9. Bb2 Be1 10. Kd1 >>>>>> Bf2 >>>>>> (3) 16-> 4:07 -0.17 1. ... Kd6 2. Bf8+ Ke6 3. f5+ gxf5 >>>>>> 4. gxf5+ Kf6 5. Bc5 h5 6. Kb1 Kf7 7. >>>>>> Ba3 Kf6 8. Kc1 h4 9. Bb2 Be1 10. Kd1 >>>>>> Bf2 >>>>>> (2) 17 6:09 -0.26 1. ... Kd6 2. Bf8+ Ke6 3. f5+ Kf6 4. >>>>>> Ba3 Bd4 5. Kb1 Bc3 6. g5+ Kf7 7. f6 >>>>>> Bd2 8. Bc1 <HT> >>>>>> 17 11:26 0.00 1. ... b2+ 2. Kc2 exf4 3. Bxc3 f3 4. >>>>>> Be1 Kd4 5. Bf2+ Kxe4 6. Ba7 Kf4 7. >>>>>> Bf2 Ke4 >>>>>> (4) 17-> 11:42 0.00 1. ... b2+ 2. Kc2 exf4 3. Bxc3 f3 4. >>>>>> Be1 Kd4 5. Bf2+ Kxe4 6. Ba7 Kf4 7. >>>>>> Bf2 Ke4 >>>>>> >>>>>>Don't know whether it will fail high at 18 or not, however... >>>>> >>>>> >>>>>depth 18 analysis: >>>>> >>>>> (3) 18 13:55 0.31 1. ... b2+ 2. Kc2 exf4 3. Bxc3 f3 4. >>>>> Be1 Kd4 5. Bf2+ Kxe4 6. Ba7 b1=Q+ 7. >>>>> Kxb1 Kd3 8. h4 Ke2 9. h5 gxh5 10. gxh5 >>>>> f2 11. Bxf2 Kxf2 12. Kc2 Ke3 >>>> >>>>I tried this on CM6000 and Rebel 10c but stopped after 30 minutes(this >>>>on an AMD 233). The 11 minutes looks impressive to me. In your final analysis >>>>on move number 9 rather than capturing with gxh5 the winning move is g5, >>>>so that the black king can capture both of white's pawns. However in an actual >>>>game Crafty would no doubt see that when it reached that point in the game. >>>> >>>>My guess is that we won't see to many people posting that program X >>>>finds this one. Hope I'm wrong in this guess. >>>> >>>>Now I'm also wondering if tablebases will help here as after the initial >>>>exchanges there remain two pawns each on the king's side? >>> >>> >>>It was definitely probing tablebases during the search. The disk was very >>>active due to the captures... >> >>Yes, Hiarcs was probing table bases during its search as well. Hiarcs found the >>solution at the 21:04 minute mark and made the move shortly there after. The >>Table Base print out that followed the Hiarcs search listing was: >> >>=+ (-0.26) depth 13/30 00:21:04 72203kn, tb=12 > > >what does "tb=12" mean? My program did over 60,000 probes. If that means only >12 were done, something is not done right in Hiarcs... Sorry Bob I do not know the answer. I can tell you that the table base search printout varied from time to time. In the Hiarcs instructions for loading the tablebases it illustrated a printout like the one i posted except the "tb=12" of course was different. I do not think that it is related to the number of probes but rather it appears to me to be a root position of the table base that the captures sent it to !. I have noted in other positional encounters that the tablebase (tb= ?) value increments random, that is to say it can jump to a very much larger value then back down to a lower value. Please, that is my obervation. It was interesting to me Bob that b2+ was Hiarcs 2nd best move in its evaluation very very early on (i wish i kept track of exactly when). On the other hand Fritz5.32 is running right now without tablebases and is at the 33 minute mark at depth 19 where as Hiarcs found the move at depth 13. I doubt it is going to find b2+ as b2+ is still down to number 11 position in Fritz5.32 evaluation. I forgot to mention Hiarcs/Fritz are running on a pentium 11 400 mhz with hash set at 128 meg. Fritz5.32 is still wrestling with the problem at the 48 minute mark and is no where near finding b2+. gonna stop it and put it out of its misery !
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