Author: Robert Hyatt
Date: 06:57:25 11/18/98
Go up one level in this thread
On November 18, 1998 at 05:00:14, Ernst A. Heinz wrote: >On November 17, 1998 at 06:36:49, Ernst A. Heinz wrote: > >>On November 16, 1998 at 18:19:53, Amir Ban wrote: >> >>>On November 16, 1998 at 14:50:57, Bruce Moreland wrote: >>> >>>>r1r1q1k1/6p1/p2b1p1p/1p1PpP2/PPp5/2P4P/R1B2QP1/R5K1 w - - 0 1 >>>> >>>>It has been contended that this move would be difficult for a computer to find, >>>>and this has caused some doubts to be raised as to whether the computer found it >>>>without assistance in this game. >>>> >>>>I would like to ask how we can clear this up absent input from DB. >>>> >>>>Has anybody run this for a long period on a micro, and if so, was any move >>>>selected other than 35. Qb6? >>>> >>>>Is the counter-attacking line 35. Qb6 Qe7 36. axb5 Rab8 37. Qxa6 e4 supposedly >>>>the reason that white shouldn't play 35. Qb6? Or is it some other line? If it >>>>is too hard or impossible to find 35. axb5, would finding this line show >>>>anything? >>>> >>>>Is there some minimum score delta we can achieve between the position after 35. >>>>axb5 and 35. Qb6 that might be evidence that DB should be given the benefit of >>>>the doubt? >>>> >>>>Are these questions unfair or wrong, if so, are their other questions that can >>>>be asked and possibly answered that will help clear this up? >>>> >>>>bruce >>> >>> >>>This is move 36 but the other details are correct. >>> >>>The first time this was discussed on CCC, Chris Whittington was still here, and >>>he reported for CSTal. It was closer than others, but still couldn't bridge the >>>gap. >> >>I fed this position into the current "DarkThought" yesterday and it liked Qb6 >>with a score of roughly +1.7 up to iteration #18 inclusively. Then, it failed >>low on Qb6 (score <= 1.39) in iteration #19 after processing 6,490,725,565 >>nodes. Currently, it is still engaged in resolving the fail-low (see below). >> >>//////////////////////////////////////////////////////////////////////////////// >> >>r1r1q1k1/6p1/p2b1p1p/1p1PpP2/PPp5/2P4P/R1B2QP1/R5K1 w - - 0 1 >> >># Clearing chess engine. >># Engine sleeps. >>- - >> +------------------------+ >>8 |*R :::*R :::*Q :::*K :::| >>7 |::: ::: ::: *P: | >>6 |*P ::: *B: *P: *P:| >>5 |:::*P ::: P *P: P ::: | >>4 | P :P:*P ::: ::: :::| >>3 |::: :P: ::: ::: P | >>2 | R ::: B ::: :Q: P :::| >>1 |:R: ::: ::: :K: | >> +------------------------+ >> a b c d e f g h >> >>14.01 Qb6 Rd8 Be4 Rac8 Qxa6 bxa4 Qxa4 Qxa4 Rxa4 Rd7 ... (1.71) #62711053 >>15.01 Qb6 Rd8 Be4 Rac8 Qxa6 bxa4 Qxa4 Qh5 Kh2 Qg5 ... (1.69) #140398448 >>16.01 Qb6 Rd8 Be4 Rac8 Qxa6 bxa4 Qxa4 Qh5 Qa7 ... (1.70) #423411650 >>17.01 Qb6 Rd8 Be4 Rac8 Qxa6 bxa4 Qxa4 Qh5 Qa7 Qh4 ... (1.73) #1230726361 >>18.01 Qb6 Rd8 Be4 a5 axb5 axb4 Rxa8 Rxa8 Rxa8 Qxa8 ... (1.64) #3337837066 >>19.01 Qb6 <=178? (1.39) #6490725565 >> >>//////////////////////////////////////////////////////////////////////////////// > >I run this on a 500MHz Alpha-21164a and the fail-low of iteration #19 got >resolved to +1.26 after 14:34 hours and 11,196,023,081 nodes (see below). > >>19.01? Qb6 Rd8 Be4 a5 axb5 axb4 Rxa8 Rxa8 Rxa8 Qxa8 ... (1.26) #11196023081 > >I will let "DarkThought" continue the calculation as long as the other people >at our institute do not get too angry at me for blocking so many Alphas ... :-) > >=Ernst= I saw some bad things happening here too. Just remember that your 11B nodes represents a few seconds to the DB hardware. I suspect that when we get deep enough, we are going to do exactly as they did... which is *not* a big surprise other than the amount of time it takes us to see this problem vs the amount of time it took them. :)
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