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Wrong Match Equity Table

by Douglas Zare
1 November 2008

Douglas Zare

One of the key advances in backgammon theory was the introduction of match equity tables by theorists such as Zadeh and Kleinmann. Experts use match equity tables to determine the true risks versus rewards in match play instead of the nominal points won or lost. Using any reasonable match equity table is better than not using anything, but now there are multiple tables in use. Woolsey has a commonly used MET, but Snowie uses its own MET, and GNU uses a different table by default. What happens when the tables conflict?

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Subject: Re: Wrong Match Equity Table

From: gibsonian Member has a photo available

Date: 05 Nov 2008 21:49 EST

Thanks Douglas, I have accumulated many of the MET's that have been published, including Snowie's 2 decimal version, Woolsey, Kleinman, Ortega-Kleinman, Strommen, Trice-Jacobs (unadjusted for the good tasting fish), Modified-Janowski, and Zadeh's1977. I use them with DoubleTakeCalculator (DTC) a piece of software that David Hart created using Kit's "Tournament Backgammon" as the model. The software accepts any MET and produces the Take-Point and Window for all the various scores and cube-sizes. It also let's you import Jellyfish data, or manually input the rollout stats (wins,G's,BG's)from any of the bots to see whether it was a DOUBLE/Redouble/Take/Drop.

I have always wanted to know how much difference there is between using one MET vs another. I am so glad that you gave us this article, because "over the table" I am not capable of using a table that uses decimal point(s) data. And only commiserate with myself (post match) when I find that Snowie would have doubled but using Woolsey I did not (or vice versa). It is nice to know that very LITTLE equity is lost between tables and read that Gammon-Go and Gammon-Save are better carried out by the trailer, than by the leader. (I will email you a screen-shot of DTC just to give you an idea of its design.)

Subject: Re: Wrong Match Equity Table

From: PhilSimborg Member has a photo available

Date: 21 Nov 2008 02:07 EST

Thanks, Doug, I too can now sleep better at night. Years ago I myself did a study using different colored dice and I too found there to be no significant difference in rolls, but I chose to keep those results to myself, thus gaining an edge on the rest of the backgammon world. I guess I am just not as good a person as you.

Phil

Subject: Re: Wrong Match Equity Table

From: mradica

Date: 23 Nov 2008 17:19 EST

Why you didn't use g11 MET produce by Zorba, instead of Ian Dunstan's, which is also obtain with GNUbg rollouts help, but is default one in mentioned bot and accepted among the non Snowie users as a best one? I guess Ian's MET is newer and done with stronger setting for rollouts but g11 is made for 11 point matches not only for 5 pointers as Dunstan's one.

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