Match Play at 2-away/2-away

Forum Archive : Match Play at 2-away/2-away

 
Counterexample?

From:   Jim Williams
Address:   jimw@giga-net.com
Date:   3 March 1998
Subject:   Re: Doubling at 2 away/ 2 away
Forum:   rec.games.backgammon
Google:   34FC4F23.3375@giga-net.com

> The below is an extract from Kit Woolsey's special report "How to Play
> Tournament Backgammon".  If you want a copy, you can contact Kit on
> FIBS.
>
> "THE TWO-AWAY VERSUS TWO-AWAY SCORE"
> ...
> Consequently, at two-away versus two-away you should always double if
> there is any chance that after the next exchange you will lose your
> market (i.e. your opponent will no longer have a take).

This does not seem to always be the case.  Consider the following
contrived example.  Half your rolls lose the game outright, and half
leave you with an 80% chance of winning the game (clearly a market
loser).

No gammons for this example.  If you double, you will win 40% of the
matches.

If you don't double, then 50% probability you lose one point (opponent
either wins or doubles you out) and 50% probability you win one point
(you double out opponent on next turn).  So not doubling leaves you with
50% match equity, which is clearly better.

 - Jim

Kit Woolsey  writes:

This would be correct if you ever reached such a position.  But how can
you get there?  If 50% of your rolls now lose outright your opponent must
have had many market losing sequences before his previous roll, so he
clearly should have doubled.  With correct play on both sides, you just
can't get from the starting position to the end of the game without the
cube being turned and accepted at this match score.

Kit
 
Did you find the information in this article useful?          

Do you have any comments you'd like to add?     

 

Match Play at 2-away/2-away

Basic strategy  (Darse Billings, Feb 1995) 
Counterexample?  (Jim Williams+, Mar 1998) 
Do you need an advantage to cube?  (Keene Marin+, Feb 2006) 
Double immediately?  (Chuck Bower, Oct 1998) 
Ever too good to double?  (Kit Woolsey, July 1995) 
Minimum game winning chances to double  (Walter Trice, Mar 1999) 
Practical strategy  (Walter Trice, July 1995) 
Practical strategy  (Albert Steg+, Feb 1995) 
Proof for doubling immediately  (Robert Koca+, May 1994) 
Proof of doubling with market losers  (Walter Trice+, July 2001) 
Sample game  (Ron Karr, Dec 1996) 

[GammOnLine forum]  From GammOnLine       [Long message]  Long message       [Recommended reading]  Recommended reading       [Recent addition]  Recent addition
 

  Book Suggestions
Books
Cheating
Chouettes
Computer Dice
Cube Handling
Cube Handling in Races
Equipment
Etiquette
Extreme Gammon
Fun and frustration
GNU Backgammon
History
Jellyfish
Learning
Luck versus Skill
Magazines & E-zines
Match Archives
Match Equities
Match Play
Match Play at 2-away/2-away
Miscellaneous
Opening Rolls
Pip Counting
Play Sites
Probability and Statistics
Programming
Propositions
Puzzles
Ratings
Rollouts
Rules
Rulings
Snowie
Software
Source Code
Strategy--Backgames
Strategy--Bearing Off
Strategy--Checker play
Terminology
Theory
Tournaments
Uncategorized
Variations

 

Return to:  Backgammon Galore : Forum Archive Main Page