Forum Archive : Rollouts

Reporting results of rollouts

From:   David Montgomery
Date:   14 June 1995
Subject:   Re: comments on instructional materials
Google:   3rn5c5$

> 1) It is sometimes not clear to me what cube protocol was used
> when rollout results are mentioned. Are there some conventions
> I am missing?

I don't think there are.  Nor can there be, really, as different
positions call for different approaches, and as the computer tools
for analyzing backgammon positions become more sophisticated, there
will be even more options.

I would like to encourage everyone (both here and in backgammon
publications) to specify the details when giving rollout results.
Assuming a JF rollout, that would mean: 1) identifying the program
(JF, not EXBG) and version (if there is more than one); 2) the
number of rollouts; 3) truncated or complete rollouts; 4) if truncated,
the horizon; 5) if not truncated, the settlement limit and the results
with the cube in the relevant positions, including cubeless results;
6) if a play vs. play comparison, whether the same random seed was
used for all plays (note that JF doesn't do this unless you specifically
enter a non-zero seed).  All of this would really only take one
sentence, like:

"For each play I did 1296 20-ply truncated rollouts with JF 1.0, using
the same random seed for each."

> 2) One thing I've been trying to do recently is expand my library
> of reference positions for over the board use. Are there any good
> annotated matches available in which comments include how expert players
> use these. For example, when to be in a reference position mindset and
> how to adjust for differences between reference and actual position.

I haven't seen anything like this in the literature.  There are only
a few references to reference positions in the annotated matches I've read
and even then the comments usually go like: "I knew this position
[reference position] was a take, and the game position looks a little
better for me, so I took."

Seems like an interesting idea, although I'm not sure if very much
in the way of general comments could be made.  Beyond establishing
reference positions, an important goal is to determine for each position
what the relevant features are, and how important changing
each of them is to the correct strategy (for checker play) or equity
(for cube play).  And a goal beyond that is to find categories of
positions such that within a category, the features behave in the
same way.

David Montgomery
monty on FIBS
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Advice  (David Montgomery, Apr 1996)  [Long message]
Cautionary tale  (Kit Woolsey, Sept 1995) 
Combining rollouts  (Gregg Cattanach+, Dec 2003)  [GammOnLine forum]
Confidence intervals  (Bob Koca, Nov 2010) 
Confidence intervals  (Timothy Chow, May 2010) 
Confidence intervals  (Gerry Tesauro, Feb 1994) 
Cubeless vs centered-cube rollouts  (Ron Karr, Dec 1997) 
Duplicate dice  (David Montgomery, June 1998) 
How reliable are rollouts?  (David Montgomery, Aug 1999) 
Level-5 versus level-6 rollouts  (Michael J. Zehr, June 1998) 
Level-5 versus level-6 rollouts  (Chuck Bower, Aug 1997) 
Positions with inaccurate rollouts  (Douglas Zare, Oct 2002) 
Reporting results of rollouts  (David Montgomery, June 1995) 
Rollout settings  (Lokicol+, Apr 2010) 
Settlement limit  (Michael J. Zehr, Apr 1998) 
Settlement limit  (Kit Woolsey, Dec 1997) 
Settlement limit in races  (Alexander Nitschke, Dec 1997) 
Some guidelines  (Kit Woolsey, Apr 1996) 
Standard error and JSD  (rambiz+, Feb 2011) 
Standard error and JSD  (Stick+, Oct 2007) 
Systematic error  (Chuck Bower, Oct 1996) 
Tips for doing rollouts  (Douglas Zare, June 2002) 
Truncated rollouts  (Gregg Cattanach, Oct 2002) 
Truncated rollouts: pros and cons  (Jason Lee+, Jan 2006)  [GammOnLine forum]
What is a rollout?  (Gregg Cattanach, Dec 1999) 

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