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Larry Kaufman

Joined: 10 Jan 2010
Posts: 1229
Location: Maryland USA

Post subject: Re: When does a cut-node became an all-node?    Posted: Thu Mar 29, 2012 1:51 am

 Daniel Shawul wrote: I haven't followed the discussion but I agree it don't make much difference to make distinction between CUT/ALL. If at a possible CUT node you don't get a cut off within the first 3 moves, then it is 99% likely that was infact an ALL node. So to benefit from CUT/ALL distinction you have to make pruning decisions within those 3 moves. Most had n_moves >= 3 for LMR which makes this rare. Infact switching the node type after searching 1 move may also be very safe. A typical example is YBW algorithm that does parallel search after searching exactly 1 move. ALL nodes are good for YBW. Another YBW variants with CUT/ALL node distinction improved it only slightly (about <= 5% from memory?) according to original inventors. PV/non-PV is a gamble where you try to have a longer PV compared to other parts of the tree. Do more extensions, less reductions at PVs etc.. Don't be surprised if that didn't work for some! You are usually comparing a certain class of engines ( engines close to Komodo) which may all be exploiting a certain optima. The rest could be working on another hill! See the discussion on singular extensions some time back that supposedly gave 40 elo to some, but actually didn't for others...

I'm not so sure that your reasoning is correct. Just because you are (let's say) on the 7th move at an expected CUT node which will probably turn out to be an ALL node, it does not follow that the previous node (or the one before that) was mis-typed; the next move tried on the previous ply may produce the cut. So it may well be that reducing the 7th move more (or less) at a CUT node than at an ALL node is still justified based on the earlier node type. At least, if this is not so, then Rybka, Ippo, Ivanhoe, Houdini, and Critter are all doing something silly. I don't believe this.
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Subject Author Date/Time
Alcides Schulz Tue Mar 27, 2012 11:55 am
Vincent Diepeveen Tue Mar 27, 2012 12:37 pm
Lucas Braesch Tue Mar 27, 2012 1:03 pm
Edmund Moshammer Tue Mar 27, 2012 1:24 pm
Vincent Diepeveen Tue Mar 27, 2012 4:52 pm
Thomas Petzke Tue Mar 27, 2012 1:28 pm
Larry Kaufman Tue Mar 27, 2012 1:46 pm
Alcides Schulz Tue Mar 27, 2012 2:03 pm
Thomas Petzke Tue Mar 27, 2012 2:42 pm
Vincent Diepeveen Tue Mar 27, 2012 5:11 pm
Larry Kaufman Tue Mar 27, 2012 6:15 pm
Vincent Diepeveen Tue Mar 27, 2012 6:22 pm
Larry Kaufman Tue Mar 27, 2012 6:31 pm
Vincent Diepeveen Tue Mar 27, 2012 6:43 pm
Larry Kaufman Tue Mar 27, 2012 7:17 pm
Vincent Diepeveen Wed Mar 28, 2012 8:00 am
Larry Kaufman Wed Mar 28, 2012 2:08 pm
Vincent Diepeveen Wed Mar 28, 2012 5:07 pm
Larry Kaufman Wed Mar 28, 2012 5:55 pm
Vincent Diepeveen Wed Mar 28, 2012 8:33 pm
Larry Kaufman Wed Mar 28, 2012 9:16 pm
Vincent Diepeveen Wed Mar 28, 2012 9:37 pm
Ed Schroder Thu Mar 29, 2012 3:22 pm
Vincent Diepeveen Wed Mar 28, 2012 8:56 pm
Larry Kaufman Wed Mar 28, 2012 9:26 pm
Vincent Diepeveen Wed Mar 28, 2012 9:59 pm
Vincent Diepeveen Wed Mar 28, 2012 10:02 pm
Larry Kaufman Wed Mar 28, 2012 10:46 pm
Ricardo Barreira Wed Mar 28, 2012 8:57 pm
Vincent Diepeveen Wed Mar 28, 2012 9:22 pm
Ricardo Barreira Thu Mar 29, 2012 9:38 am
Vincent Diepeveen Thu Mar 29, 2012 9:45 am
Marco Costalba Tue Mar 27, 2012 6:37 pm
Robert Hyatt Tue Mar 27, 2012 5:19 pm
Vincent Diepeveen Tue Mar 27, 2012 5:35 pm
Steve Maughan Tue Mar 27, 2012 5:59 pm
Robert Hyatt Tue Mar 27, 2012 5:12 pm
Alcides Schulz Tue Mar 27, 2012 5:41 pm
Robert Hyatt Wed Mar 28, 2012 10:01 pm
Larry Kaufman Wed Mar 28, 2012 10:31 pm
Daniel Shawul Thu Mar 29, 2012 12:28 am
Re: When does a cut-node became an all-node? Larry Kaufman Thu Mar 29, 2012 1:51 am
Sam Hamilton Thu Mar 29, 2012 2:05 am
Larry Kaufman Thu Mar 29, 2012 2:37 am
Sam Hamilton Thu Mar 29, 2012 2:56 am
Vincent Diepeveen Thu Mar 29, 2012 9:36 am
Ed Schroder Thu Mar 29, 2012 4:01 pm
Daniel Shawul Thu Mar 29, 2012 10:53 am
Larry Kaufman Thu Mar 29, 2012 2:24 pm
Daniel Shawul Thu Mar 29, 2012 4:04 pm
Daniel Shawul Thu Mar 29, 2012 4:27 pm
Larry Kaufman Thu Mar 29, 2012 5:49 pm
Daniel Shawul Thu Mar 29, 2012 7:18 pm
Larry Kaufman Thu Mar 29, 2012 4:28 pm
Daniel Shawul Thu Mar 29, 2012 4:52 pm
Larry Kaufman Thu Mar 29, 2012 5:58 pm
Daniel Shawul Thu Mar 29, 2012 7:13 pm
Karlo Bala Jr. Thu Mar 29, 2012 8:39 pm
Daniel Shawul Thu Mar 29, 2012 9:02 pm
Karlo Bala Jr. Thu Mar 29, 2012 9:23 pm
Daniel Shawul Thu Mar 29, 2012 9:45 pm
Vincent Diepeveen Fri Mar 30, 2012 12:26 am
Robert Hyatt Thu Mar 29, 2012 8:34 pm
Alcides Schulz Thu Mar 29, 2012 3:05 am
Thomas Petzke Thu Mar 29, 2012 6:53 am

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