Author: Uri Blass
Date: 04:18:42 05/20/03
Go up one level in this thread
On May 20, 2003 at 06:22:22, Uri Blass wrote: >On May 20, 2003 at 03:50:58, Tony Werten wrote: > >>On May 20, 2003 at 02:17:14, Tim Foden wrote: >> >>>On May 19, 2003 at 23:46:58, Will Singleton wrote: >>> >>>>I was trying to figure out why my latest build doesn't do quite as well on >>>>ecm86, and I ran Ruffian on it. To my surprise, Ruffian couldn't solve it, even >>>>given 5 minutes. This is odd, since most other progs can do it in less than 10 >>>>seconds. (What I take away from this exercise is that my program must now be >>>>stronger. Otherwise, I'd have to work on the problem, which is much less >>>>interesting than testing new ideas.) >>>> >>>>[D]2r3k1/1nqbrp2/p5pp/1p1Pp1N1/8/1P5P/P1B2PP1/2RQR1K1 w - - >>> >>>I would assume then (from running Green Light), that Nxf7 is the correct move >>>here? >>> >>>The PV is interesting as it contains 9 captures in a row at the start of the PV. >>> Maybe ruffian is pruning if there are more than a certain number of captures in >>>a row (as this is very unlikely to be a good thing). >> >>My guess is that Ruffian is a preprocessor, which can't handle 9 captures >>because the position is so different ( root position compared to leaf position ) >> >>There is a good chance Fritz 5.32 will show the same beheavior. >> >>Tony > >Your guess seems to be wrong and if I do the moves Nxf7 Rxf7 and take them back >Ruffian has no problem to find Nxf7. > >Fritz5.32 also has no problem with that move. >I believe that being preprocessor is a bad idea so my default assumption(unless >other things are provedO) is that Ruffian is not a preprocessor. > >I guess that some pruning that is not null move pruning prevents it to see Nxf7 >in a reasonable time. > >Uri Note also that if I give Ruffian an hour to analyze then it can see Nxf7 depth=16 +1.75 Nxf7 Rxf7 Bxg6 Qxc1 Bxf7+ Kxf7 Qh5+ Kg7 Qxe5+ Kg6 Rxc1 Rxc1+ Kh2 Rc8 Qe3 Nc5 b4 Na4 Qa7 Rd8 Qxa6+ Kg5 Nodes: 1393992604 NPS: 406222 Time: 00:57:11.60 Uri
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