GNU Backgammon

Forum Archive : GNU Backgammon

Rollout settings

From:   geoff arnold
Date:   17 April 2007
Subject:   Gnu Questions..
Forum:   BGonline

I have used Snowie for years as my main option for analyzing match's and
rollouts etc. I have had Gnu as well for years just mainly as another
option. GNU for me is more effective speed wise in terms of delivering a
fast result and fairly accurate etc..

My question is:  What settings do you use for rollouts with gnu? What MET
should I use? I currently have it set as G11.

BTW I have been to and have seen
his suggestions. I am just wondering if these are accurate enough in your

Daniel Murphy  writes:

My default rollouts settings that I use for 95% of my rollouts are:

    * Trials -- depends on how close the plays are and how accurate I want
    the equities to be. You can judge from the evaluations how many trials
    might be needed. I run a minimum of 108 trials and usually 324, 648,
    1296 or more, but I would emphasize that you do not need to run 1296
    trials of every rollout and it's really not necessary that the number
    of trials is divisible by 36. In a rollout I'm looking for a JSD of 3.
    Once I get that, more trials are extremely unlikely to change the
    decision and will only make the equities more accurate.
    * Truncation OFF
    * Evaluation for later plies OFF
    * Stop when result is accurate OFF
    * Stop rollouts of multiple ... OFF
    * Cubeful ON
    * Variance reduction ON
    * Quasi-random dice ON
    * Rollout as initial position OFF
    * Cube decisions same settings OFF
    * Use same settings for both players ON
    * Use player0 setting for truncation point ON
    * Checker play: 2-ply
    * Cube: 2-ply
    * Use neural net pruning ON
    * Cubeful checker evaluation ON
    * Move filter NARROW
    * MET = G11

Albert's suggestions at AllAboutGNU are reasonable. I agree that "0-ply
checker play is indeed extremely strong" and since it is fast it gets
results in good time but since I usually weigh accuracy more heavily than
speed I do not agree that 0-ply is "usually ideal for full rollouts." I
don't use 0-ply checker play except for simple noncontact positions and
never use 0-ply cube. Even in the simplest of contact positions, like a
bearoff against checkers on the roof, 0-ply and 2-ply GWCs may differ by 1%
or more. Albert's "third setting" recommendations are o.k. The Ians'
rollouts with "separate evaluations" enabled changing to 0-ply checker play
after 12 plies have usually gotten good results compared to full 2-ply
rollouts but if the position is likely to be complex after 12 plies then a
full 2-ply rollout would be a better choice. I have found that there is
very little difference in results between 2-ply with Narrow, Large (world
class) and Huge (supremo) move filters.
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GNU Backgammon

Analyzing GamesGrid matches  (Roy Passfield, Dec 2001) 
Batch analysis tool  (Øystein Johansen, June 2004)  [GammOnLine forum]
Cache size  (Ned Cross+, Mar 2004)  [GammOnLine forum]
Compiling for Windows  (Øystein Johansen, Jan 2002) 
Edit mode removing checker from bar  (Scott Steiner+, May 2003) 
Entering an annotated match  (Albert Silver, Dec 2003)  [GammOnLine forum]
Error rates: Gnu vs. Snowie  (Raccoon, Mar 2006)  [GammOnLine forum]
Even-ply/odd-ply effect  (Raccoon, Nov 2004) 
Even-ply/odd-ply effect  (Tom Keith+, Oct 2003) 
Even-ply/odd-ply effect  (Scott Steiner+, Dec 2002) 
Filter settings  (Robert-Jan Veldhuizen, Nov 2004)  [GammOnLine forum]
Gnu 0.13 versus Jellyfish and Snowie  (Torsten Schoop, Aug 2003) 
Gnu 0.13 vs. Snowie 4  (Albert Silver, June 2003) 
Gnu 0.14 vs. Jellyfish  (Michael Howard+, July 2003) 
Gnu versus Snowie and Jellyfish  (Michael Depreli, Oct 2005) 
How luck factor is calculated  (Gregg Cattanach, Aug 2002) 
How rollouts work  (Gary Wong, July 1999) 
How to enter an illegal move  (Øystein Johansen, Aug 2003)  [GammOnLine forum]
Importing .gam files  (PAR+, Mar 2005) 
Importing PartyGammon matches  (rew+, July 2006) 
Improving your game using GnuBG  (D.U.G.+, Nov 2002) 
Installing on Windows  (maareyes, Oct 2001) 
Interpreting JSD's  (Adrian Wright+, Feb 2005)  [GammOnLine forum]
JSD's and confidence intervals  (Daniel Murphy+, Jan 2005) 
Logging rollouts  (Øystein Johansen, Oct 2004)  [GammOnLine forum]
Luck rate  (Kees van den Doel+, May 2002) 
MWC versus Equity (EMG)  (Ken+, Apr 2005)  [GammOnLine forum]
Manually entering first roll  (Andreas Graf+, Apr 2005) 
Match equity tables  (Raccoon, July 2005)  [GammOnLine forum]
Personal reflections  (Louis Nardy Pillards, Sept 2002) 
Playing two computers against each other  (Stanley E. Richards+, Mar 2008)  [GammOnLine forum]
Python scripting  (Øystein Johansen+, Nov 2004) 
Quasi-random dice in rollouts  (Ian Shaw, Mar 2004)  [GammOnLine forum]
Question marks in game list  (Jim Segrave, July 2005) 
Questions and answers  (Jim Segrave+, Jan 2003) 
Questions and answers  (Jørn Thyssen, Aug 2002) 
Restarting a rollout with different settings  (Jim Segrave, Apr 2005)  [GammOnLine forum]
Restarting a rollout with different settings  (Robert-Jan Veldhuizen, Apr 2004)  [GammOnLine forum]
Rollout settings  (geoff arnold+, Apr 2007) 
Rollout settings  (Stick+, Nov 2005)  [GammOnLine forum]
Rollout settings  (Robert-Jan Veldhuizen, Mar 2004)  [GammOnLine forum]
Rollout settings  (Ian Dunstan, Aug 2003)  [GammOnLine forum]
Rollout settings for the impatient  (Robert-Jan Veldhuizen, June 2004)  [GammOnLine forum]
Running rollouts in background  (Bruce+, Apr 2004)  [GammOnLine forum]
Saving rollout results from command-line interface  (Jeremy Bagai+, Apr 2006)  [GammOnLine forum]
Saving rollouts  (Mislav Radica+, May 2006)  [GammOnLine forum]
Setting GnuBG's playing strength  (JP White, Sept 2001) 
Setting skill level  (Jim Segrave, Apr 2004) 
Setting up and saving a rollout  (Albert Silver, Dec 2003)  [GammOnLine forum]
What's GNU?  (Gary Wong, Oct 2001) 
Which player is player 0?  (Neil Kazaross+, Oct 2004)  [GammOnLine forum]

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