GNU Backgammon

Forum Archive : GNU Backgammon

Questions and answers

From:   Jørn Thyssen
Date:   5 August 2002
Subject:   Re: GNU

> I've been trying out GNU for a while and must say I'm quite impressed.
> I don't think it (yet?) matches Snowie, especially when it comes to user
> interface and stuff like that. I do however have a few questions:

> After analyzing a match I'm told (among other things) that I've done
> mistakes. Is there any way to see what mistakes I've done?

They are marked with !, !!, ? or !? in the game list (windows->game list).

> Is there a way to make GNU "sort" the dice, i.e. make the bigger die
> appear first. If I roll 13 I automatically read this as a 31 so instead
> of making the 5-point I end up moving 8/7, 6/3.

Settings->Appearence->General->Show higher die on the left

> Is it possible to right-click when you just want to bear two checkers
> off?

No, but you may use Settings->Options->Automatic->Bearoff.

> When doing rollouts I often find that the cubeless vs cubeful results
> differ quite a bit. Is the cubeful equity always more correct?

Not necesarily, but they take the value of holding the cube into
account. In general, you cannot compare cubeful and cubeless equities.

For example,

  GNU Backgammon  Position ID: DwAA4AEAAAAAAA
                  Match ID   : cAkAAAAAAAAA
  +13-14-15-16-17-18------19-20-21-22-23-24-+     O: gnubg
  |                  |   |                O | OOO 0 points
  |                  |   |                O | OO
  |                  |   |                O | OO
  |                  |   |                O | OO
  |                  |   |                  | OO
 v|                  |BAR|                  |     (Cube: 1)
  |                  |   |                  | XX
  |                  |   |                X | XX
  |                  |   |                X | XX
  |                  |   |                X | XX  On roll
  |                  |   |                X | XXX 0 points
  +12-11-10--9--8--7-------6--5--4--3--2--1-+     X: jth

The cubeless equity is +0.722, but the cubeful equity is:

Centered cube: +1.000 (double, pass)
X owns cube  : +1.000 (redouble, pass)
O owns cube  : +0.722

So for centered and X owning cube the cubeless equity is 0.278 from the
"true" equity.

> Will it be possible to save & open matches & positions directly to/from
> Snowie formats?

No, the Snowie formats are binary and not documented anywhere. You can
export matches from Snowie in .mat (Jellyfish format) and import those
into gnubg, but any analysis will be lost.

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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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