ChessUSA.com TalkChess.com
Hosted by Your Move Chess & Games
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

When does a cut-node became an all-node?
Post new topic    TalkChess.com Forum Index -> Computer Chess Club: Programming and Technical Discussions Flat
View previous topic :: View next topic  
Author Message
Larry Kaufman



Joined: 10 Jan 2010
Posts: 1228
Location: Maryland USA
PostPost subject: Re: When does a cut-node became an all-node?    Posted: Wed Mar 28, 2012 5:55 pm Reply to topic Reply with quote
diep wrote:
[snip]

lkaufman wrote:
diep wrote:

Reducing 1 ply is the mathematical optimum, basically reduction of 1 ply is still what's getting done in the end by most of todays engines, be it in a more risky way. Also that it's the mathematical optimum between risk and reduction of search tree doesn't mean that taking more risk isn't gonna work for you Smile

I don't understand how there can be a mathematical optimum reduction, it should depend on how good your move ordering is. If it's good enough, you could reduce all moves after the first by 100 plies!

Well now you write as how we did do computerchess in the 90s. Namely using the extreme assumptions. We already know for a year or 13, that the fliprate (heh another computerchess statistic i introduced back then) of crafty was around a 5% and of Diep it was far lower, between 1% and 2% at the time. Probably that's different nowadays, especially crafty will have improved and with it most of the modern beancounters, but not *that much* better than it used to be.

So we can safely assume that reducing things 100 ply is too much of a risk. The mathematical optimum between risk and profit is then 1 ply. In how i wrote that down, that means simply this breaks even a lot quicker.

If you fiddle some with chances you'll also end up there.

Reducing 2 ply, simply is very very risky as compared to reducing 1 ply. Which doesn't mean that you shouldn't try doing that if you already get 20+ ply anyway Smile

A pragmatic approach there isn't gonna get punished...




Three questions:
1. Could you please define "fliprate"?
2. What assumptions are made in your proof that the ideal LMR reduction is just 1 ply?
3. What is your opinion of the idea of increasing the null move reduction with increased depth? Stockfish pushes this to the extreme, adding another ply of reduction for each 4 plies of search. I imagine you will think it is a bad idea, but I don't like to assume such things.

Larry
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Subject Author Date/Time
When does a cut-node became an all-node? Alcides Schulz Tue Mar 27, 2012 11:55 am
      Re: When does a cut-node became an all-node? Vincent Diepeveen Tue Mar 27, 2012 12:37 pm
      Re: When does a cut-node became an all-node? Lucas Braesch Tue Mar 27, 2012 1:03 pm
            Re: When does a cut-node became an all-node? Edmund Moshammer Tue Mar 27, 2012 1:24 pm
                  Re: When does a cut-node became an all-node? Vincent Diepeveen Tue Mar 27, 2012 4:52 pm
            Re: When does a cut-node became an all-node? Thomas Petzke Tue Mar 27, 2012 1:28 pm
      Re: When does a cut-node became an all-node? Larry Kaufman Tue Mar 27, 2012 1:46 pm
            Re: When does a cut-node became an all-node? Alcides Schulz Tue Mar 27, 2012 2:03 pm
            Re: When does a cut-node became an all-node? Thomas Petzke Tue Mar 27, 2012 2:42 pm
            Re: When does a cut-node became an all-node? Vincent Diepeveen Tue Mar 27, 2012 5:11 pm
                  Re: When does a cut-node became an all-node? Larry Kaufman Tue Mar 27, 2012 6:15 pm
                        Re: When does a cut-node became an all-node? Vincent Diepeveen Tue Mar 27, 2012 6:22 pm
                              Re: When does a cut-node became an all-node? Larry Kaufman Tue Mar 27, 2012 6:31 pm
                                    Re: When does a cut-node became an all-node? Vincent Diepeveen Tue Mar 27, 2012 6:43 pm
                                          Re: When does a cut-node became an all-node? Larry Kaufman Tue Mar 27, 2012 7:17 pm
                                                Re: When does a cut-node became an all-node? Vincent Diepeveen Wed Mar 28, 2012 8:00 am
                                                      Re: When does a cut-node became an all-node? Larry Kaufman Wed Mar 28, 2012 2:08 pm
                                                            Re: When does a cut-node became an all-node? Vincent Diepeveen Wed Mar 28, 2012 5:07 pm
                                                                  Re: When does a cut-node became an all-node? Larry Kaufman Wed Mar 28, 2012 5:55 pm
                                                                        Re: When does a cut-node became an all-node? Vincent Diepeveen Wed Mar 28, 2012 8:33 pm
                                                                              Re: When does a cut-node became an all-node? Larry Kaufman Wed Mar 28, 2012 9:16 pm
                                                                                    Re: When does a cut-node became an all-node? Vincent Diepeveen Wed Mar 28, 2012 9:37 pm
                                                                                          Re: When does a cut-node became an all-node? Ed Schroder Thu Mar 29, 2012 3:22 pm
                                                                        Re: When does a cut-node became an all-node? Vincent Diepeveen Wed Mar 28, 2012 8:56 pm
                                                                              Re: When does a cut-node became an all-node? Larry Kaufman Wed Mar 28, 2012 9:26 pm
                                                                                    Re: When does a cut-node became an all-node? Vincent Diepeveen Wed Mar 28, 2012 9:59 pm
                                                                                          Re: When does a cut-node became an all-node? Vincent Diepeveen Wed Mar 28, 2012 10:02 pm
                                                                                          Re: When does a cut-node became an all-node? Larry Kaufman Wed Mar 28, 2012 10:46 pm
                                                      Re: When does a cut-node became an all-node? Ricardo Barreira Wed Mar 28, 2012 8:57 pm
                                                            Re: When does a cut-node became an all-node? Vincent Diepeveen Wed Mar 28, 2012 9:22 pm
                                                                  Re: When does a cut-node became an all-node? Ricardo Barreira Thu Mar 29, 2012 9:38 am
                                                                        Re: When does a cut-node became an all-node? Vincent Diepeveen Thu Mar 29, 2012 9:45 am
                              Re: When does a cut-node became an all-node? Marco Costalba Tue Mar 27, 2012 6:37 pm
            Re: When does a cut-node became an all-node? Robert Hyatt Tue Mar 27, 2012 5:19 pm
                  Re: When does a cut-node became an all-node? Vincent Diepeveen Tue Mar 27, 2012 5:35 pm
            Re: When does a cut-node became an all-node? Steve Maughan Tue Mar 27, 2012 5:59 pm
      Re: When does a cut-node became an all-node? Robert Hyatt Tue Mar 27, 2012 5:12 pm
            Re: When does a cut-node became an all-node? Alcides Schulz Tue Mar 27, 2012 5:41 pm
                  Re: When does a cut-node became an all-node? Robert Hyatt Wed Mar 28, 2012 10:01 pm
                        Re: When does a cut-node became an all-node? Larry Kaufman Wed Mar 28, 2012 10:31 pm
                              Re: When does a cut-node became an all-node? 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
                                          Re: When does a cut-node became an all-node? Sam Hamilton Thu Mar 29, 2012 2:05 am
                                                Re: When does a cut-node became an all-node? Larry Kaufman Thu Mar 29, 2012 2:37 am
                                                      Re: When does a cut-node became an all-node? Sam Hamilton Thu Mar 29, 2012 2:56 am
                                                Re: When does a cut-node became an all-node? Vincent Diepeveen Thu Mar 29, 2012 9:36 am
                                                      Re: When does a cut-node became an all-node? Ed Schroder Thu Mar 29, 2012 4:01 pm
                                          Re: When does a cut-node became an all-node? Daniel Shawul Thu Mar 29, 2012 10:53 am
                                                Re: When does a cut-node became an all-node? Larry Kaufman Thu Mar 29, 2012 2:24 pm
                                                      Re: When does a cut-node became an all-node? Daniel Shawul Thu Mar 29, 2012 4:04 pm
                                                            Re: When does a cut-node became an all-node? Daniel Shawul Thu Mar 29, 2012 4:27 pm
                                                                  Re: When does a cut-node became an all-node? Larry Kaufman Thu Mar 29, 2012 5:49 pm
                                                                        Re: When does a cut-node became an all-node? Daniel Shawul Thu Mar 29, 2012 7:18 pm
                                                            Re: When does a cut-node became an all-node? Larry Kaufman Thu Mar 29, 2012 4:28 pm
                                                                  Re: When does a cut-node became an all-node? Daniel Shawul Thu Mar 29, 2012 4:52 pm
                                                                        Re: When does a cut-node became an all-node? Larry Kaufman Thu Mar 29, 2012 5:58 pm
                                                                              Re: When does a cut-node became an all-node? Daniel Shawul Thu Mar 29, 2012 7:13 pm
                                                                                    Re: When does a cut-node became an all-node? Karlo Bala Jr. Thu Mar 29, 2012 8:39 pm
                                                                                          Re: When does a cut-node became an all-node? Daniel Shawul Thu Mar 29, 2012 9:02 pm
                                                                                          Re: When does a cut-node became an all-node? Karlo Bala Jr. Thu Mar 29, 2012 9:23 pm
                                                                                          Re: When does a cut-node became an all-node? Daniel Shawul Thu Mar 29, 2012 9:45 pm
                                                                                          Re: When does a cut-node became an all-node? Vincent Diepeveen Fri Mar 30, 2012 12:26 am
                              Re: When does a cut-node became an all-node? Robert Hyatt Thu Mar 29, 2012 8:34 pm
                        Re: When does a cut-node became an all-node? Alcides Schulz Thu Mar 29, 2012 3:05 am
                        Re: When does a cut-node became an all-node? Thomas Petzke Thu Mar 29, 2012 6:53 am
Post new topic    TalkChess.com Forum Index -> Computer Chess Club: Programming and Technical Discussions

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum




Powered by phpBB © 2001, 2005 phpBB Group
Enhanced with Moby Threads