Rollouts

Forum Archive : Rollouts

Duplicate dice From:   David Montgomery Address:   monty@cs.umd.edu Date:   21 June 1998 Subject:   Re: Snowie v. JellyFish Forum:   rec.games.backgammon Google:   6mjjd4$e71@krackle.cs.umd.edu > Do duplicate dice reduce the variance compared to random dice, and if so, > by how much?" I investigated this with JF rollouts, and my results were that duplicate dice didn't help at all. Fredrik told me that "these techniques are far less effective than you might think," but he was surprised that I didn't find any benefit. He felt that the benefit for races and priming games should be pretty big. My experiments were pretty crude, but I don't think duplicate dice are worth much for most positions. However, there is one situation where they have a lot more promise. This is when you are going to roll out the *same* play at different match scores. As Chuck wrote, the problem with using duplicate dice for play vs play rollouts is that the positions quickly diverge, and so what is lucky in one position may be unlucky in the other. However, if we are rolling out the same position at two different match scores, we might expect that the two rollouts would diverge much more slowly, since they start out the same, and very often the correct play at one score will also be correct at the other. David Montgomery monty@cs.umd.edu monty on FIBS   Did you find the information in this article useful?           Do you have any comments you'd like to add?

 

Rollouts

Advice  (David Montgomery, Apr 1996) 

Cautionary tale  (Kit Woolsey, Sept 1995) 

Combining rollouts  (Gregg Cattanach+, Dec 2003) 

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) 

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) 

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) 

What is a rollout?  (Gregg Cattanach, Dec 1999) 

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