Author: Tony Werten
Date: 10:10:32 01/15/02
Go up one level in this thread
On January 14, 2002 at 20:14:26, Dann Corbit wrote: >On January 12, 2002 at 12:42:19, Tony Werten wrote: > >>On January 11, 2002 at 14:27:47, Dann Corbit wrote: >> >>>On January 11, 2002 at 13:00:46, Miguel A. Ballicora wrote: >>> >>>>On January 11, 2002 at 12:47:29, David Rasmussen wrote: >>>> >>>>>On January 11, 2002 at 12:40:03, Matthias Gemuh wrote: >>>>> >>>>>>On January 11, 2002 at 11:44:39, David Rasmussen wrote: >>>>>> >>>>>>>[D]2Q2n2/2R4p/1p1qpp1k/8/3P3P/3B2P1/5PK1/r7 w - - 0 1 >>>>>>> >>>>>>>In the above position, my search tree explodes because of extensions. It takes > >>>>>>>3 minutes and 42 million nodes to finish an 8 ply search. How does your program >>>>>>>do? >>>>>>> >>>>>>>Any good ideas on how to limit extensions in such a position. >>>>>>> >>>>>>>P.S. Solving the position is no problem. It is a simple mate in 5 plies, and is >>>>>>>found very early on at depth 1 or 2 or so. Still, there must be something >>>>>>>unsound about my extensions, or at least room for improvement, when this >>>>>>>position makes the tree explode. >>>>>>> >>>>>>>/David >>>>>> >>>>>> >>>>>> >>>>>> >>>>>>My HyLogicChess has the following stats: >>>>>>All extensions active. >>>>>>Quiescence moves: 29% (no explosion, my average is normally have 40%) >>>>>>Total moves searched: 11000 >>>>>>Speed; 84 kN/s >>>>>>Move Ordering: 78% (normally 90%..92%) >>>>>>[1] (0.18) 1.f3 (00h:00m:00s) >>>>>>[2] (0.12) 1.Qb7 e5 (00h:00m:00s) >>>>>>[3] (14.50) 1.Qxf8 Kh5 2.Rxh7 Kg4 3.Qxd6 (00h:00m:00s) >>>>>>[4] (+Mate in 3) 1.Qxf8 Kh5 2.Rxh7 Kg4 3.f3 (00h:00m:00s) >>>>> >>>>>My program performs similarly if only searching to ply 4, but try letting it >>>>>search to ply 9, even though it has already found the mate. That is what I am >>>>>talking about. >>>>> >>>>>/David >>>> >>>>Gaviota's output: >>>> >>>>setboard 2Q2n2/2R4p/1p1qpp1k/8/3P3P/3B2P1/5PK1/r7 w - - 0 1 >>>>d >>>>+-----------------+ >>>>| . . Q . . n . . | >>>>| . . R . . . . x | >>>>| . x . q x x . k | >>>>| . . . . . . . . | >>>>| . . . o . . . o | >>>>| . . . B . . o . | >>>>| . . . . . o K . | >>>>| r . . . . . . . | >>>>+-----------------+ >>>> >>>>sd 9 >>>>go >>>> 104 1: 0.0 +30.78 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8xd6 >>>> 392 2: 0.0 +30.78 Qc8xf8 Kh6-h5 Rc7xh7 <EMPTY> >>>> <-transp >>>> 455 3 0.0 :-) Qc8xf8 >>>> 530 3 0.0 :-) Qc8xf8 >>>> 565 3 0.0 :-) Qc8xf8 >>>> 1637 3 0.0 :-) Qc8xf8 >>>> 3104 3: 0.0 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 4023 4 0.1 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 4475 4: 0.1 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 5444 5 0.1 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 8853 5: 0.1 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 11891 6 0.1 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 18148 6: 0.2 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 24692 7 0.2 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 48189 7: 0.4 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 62166 8 0.6 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 152926 8: 1.5 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 172449 9 1.6 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> 262305 9: 2.3 +Mat_3 Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 >>>> Qf8-g8 >>>> >>>>Ply: 9 >>>>Qc8xf8 Kh6-h5 Rc7xh7 Kh5-g4 Qf8-g8 >>>>Score: 125.37 (32094) Evals: 90689 Time: 2.3s nps: 115400 Q/all: 0.36 >>>> nodes cutoffs missed tree_exp >>>>path 168830 26576 823 1.03 >>>>quies 93475 31592 1083 1.03 >>>>all 262305 58168 1906 1.03 >>>>hashtable= attempts: 284553 hits: 35.3% perfect: 23.2% >>>>move c8f8 >>> >>>For a mate in 3, it does not make any sense to search past ply 5 if you already >>>see it. After all, when you have searched ply 5 and have a mate in 3, you >>>cannot possibly improve it. >> >>Yes you can. Nullmove and pruning can take care of hiding a short mate until >>deeper searchdepth. >> >>The safe assumption is that when you have a mate in 5 ply and you're deeper than >>4 ply in the search you can cut off since it will not improve the score. > >That's the same thing I said. Yes you did. I read in another thread that someone thought you don't have to search more than 5 ply from the root, and thought you meant the same. Sorry, Tony
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