Miscellaneous

Forum Archive : Miscellaneous

 
Checker play versus cube play

From:   David Montgomery
Address:   monty@cs.umd.edu
Date:   14 January 1998
Subject:   Re: JellyFish faults
Forum:   rec.games.backgammon
Google:   69j594$9l0@twix.cs.umd.edu

Daniel Murphy wrote a very nice article on Jellyfish's style and
strengths and weaknesses, with a listing of several mistakes that
Jellyfish makes, mostly from the bearoff where we can calculate the
correct actions.  I just want to comment on one paragraph Daniel
wrote on the relative importance of cube and checker play.

> Bad takes -- positional judgement and cube strategy are the most
> challenging aspects of modern backgammon.

I disagree.  I think checker play is more challenging.  Why?

1) You are faced with many, many more tough checker plays than
   cube actions per game.
2) Even beyond the surplus of tough checker plays that occur in
   a game, there are many more tough checker plays than cube
   actions.  Here's an exercise.  Take a few interesting doubling
   positions.  Now, go through all the rolls for the leader and
   see how you would play them.  You will find that for each
   interesting doubling decision, there are several interesting
   checker plays.  And of course most positions that are not
   interesting with respect to the cube have several interesting
   checker plays on particular rolls.
3) Prior to the availability of computer rollouts, checker play
   theory necessarily lagged far behind cube theory because it
   is much more difficult to roll out checker plays.  You have to
   roll out several candidates, and they are probably close.
4) Even now that we have computer rollouts, it is much more difficult
   to investigate checker plays.  You typically have to rollout
   three times as many positions, and each has to be rolled out
   for more games.
5) Beyond the extra effort of doing the more rollouts, at this point
   you have to invent theory because there is so little out there.
6) There are many more kinds of decisions in checker plays.  Most
   interesting cube decisions are (re)double/no (re)double decisions
   or take/drop decisions.  In checker plays, you have questions
   on whether to break an anchor, to make an offensive or defensive
   point, to hit loose or hit and cover, etc.  Generally, the same
   kinds of factors go into both checker plays and cube decisions
   -- how strong is my board? how strong is my opponents? how flexible
   am I?  will I be able to clear this point?  etc. -- but with
   checker plays you are applying them to several kinds of decisions.
   (One might protest, ah but you have take/drop decisions in holding
   games, backgames, blitzes, etc.  I would respond that for each of
   these kinds of games, there are many types of checker play decisions.)
7) When you don't have a model for cube actions, you can often
   get by using a reference position.  But reference positions are
   much less useful for checker plays.  This is because the number of
   types of decisions is greater, and since checker plays are often
   closer than cube decisions, small inaccuracies in your mental
   adjustments to your reference positions are more likely to
   lead to the wrong decision.

> It's not easy to learn to play the checkers competitively, but
> it's much more difficult, especially in match play, to double
> neither too soon nor too late, and to drop or take correctly.

We haven't really defined "competitively", but lets look at it
this way -- consider the class A of players who on average maintain
a rating of X.  Let's say you currently play at a lower level than
players in A.  Is it easier to get your checker play up to the level
of A players or to get your cube action up to the A level?

I think it is easier to get your cube play up to this new level,
although I'm not sure.  I think there is less you need to study (i.e.,
you can often get by with reference positions) and there is less need
for an appreciation of subtle changes in a position.  Also, for
players who don't study, I suspect their checker play is better
than their cube play (since they get more practice at it, and
comments on it in chouettes), so players who do study can have
relatively better cube play.

Regarding match adjustments, it is certainly true that cube play
becomes much tougher, but so does checker play.  Good players have
a strong appreciation for how to change their cube action based
on a match situation, but I believe they are worse at adjusting
their checker play.

> Among advanced and even expert players, errors with the cube
> tend to be much more costly than mistakes in checker play.

This is true when you compare a single checker play error to
a single cube error.  But since there are many more checker play
errors per game, I believe that in total, human experts (and
everyone else) give up more equity due to checker play mistakes
than due to cube errors.

> Perhaps this -- cube handling -- is JellyFish's biggest advantage
> over human players, including experts.

Perhaps, but especially against experts, I think it's the other
way around.  I think Jellyfish's bigger advantage against strong
players is in checker play.

(In matches I think Jellyfish does adjust its cube action better than
human players, because it is uniformly good at estimating probabilities,
whereas human players are more keenly attuned to money doubling and
taking points.  Where Jellyfish adjusts its checker play evaluations,
at DMP, Crawford, post-Crawford, and some other situations, I'm certain
it does a better job of adjusting its play that almost everyone.  Where
it doesn't, humans can get a small edge.)

I think checker play theory is the frontier in backgammon research.

David Montgomery
monty on FIBS
monty@cs.umd.edu
 
Did you find the information in this article useful?          

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

 

Miscellaneous

Backgammon computers  (Graham Bayne+, Mar 2005) 
Backgammon in famous paintings  (Dan Scoones, Mar 2000) 
Backgammon versus poker  (Peter Hallberg, June 2006) 
Backgammon's popularity  (Anon+, Sept 2003) 
Board orientation  (Daniel Murphy, Mar 1999) 
Calculation versus instinct  (Kit Woolsey, Jan 1998) 
Checker play versus cube play  (Gregg Cattanach, Oct 2004) 
Checker play versus cube play  (David Montgomery, Jan 1998)  [Recommended reading]
Copying positions from books  (Stick+, Nov 2005) 
Famous people who play  (Carem Wiklicm+, Dec 2002) 
Free lesson  (Donald Kahn, Apr 1999) 
General tips  (Hank Youngerman, Aug 1998) 
Giants of Backgammon list  (Raccoon+, Mar 2006)  [GammOnLine forum]
Handicapping  (Kees van den Doel+, Aug 2003) 
Handicapping  (flash, Aug 1998) 
Handicapping--Pass or pick a roll  (Michael J. Zehr, Dec 1997) 
Handicapping--Rerolling 5-4  (Mary Hickey, Feb 2004)  [GammOnLine forum]
How bots rate you  (Phil Simborg, Mar 2010) 
Initiatives by local clubs  (Raccoon, Mar 2006)  [GammOnLine forum]
Is online gambling legal in the U.S.?  (Chuck Bower+, June 2006)  [GammOnLine forum]
Maximizing earnings  (Stanley E. Richards+, Oct 2005)  [GammOnLine forum]
Money management  (Carly Robson+, Jan 2009) 
Money management  (Gnoh Mon+, July 2004) 
Money management  (Adam Stocks, Jan 2003) 
Money management and the Kelly Criterion  (Stuart Thomson+, June 1999)  [Long message]
Notation  (Dean Gay, Feb 2000) 
Notation  (Kit Woolsey, July 1995) 
Position cards  (Francois Hochede, Jan 2004) 
Posted diagrams are scrunched up  (Dale+, Sept 2000) 
Top women players  (Tami+, Nov 2006)  [GammOnLine forum]
Typesetting backgammon  (Jason Lee+, Apr 2006)  [GammOnLine forum]
What is Zbot?  (Douglas Zare+, Dec 2003)  [GammOnLine forum]
What is backgammon?  (David C. Oshel, Aug 1997) 
Why do people play for money?  (Hank Youngerman+, Sept 2005) 
World Champions  (John Bazigos, June 1994) 
rec.games.backgammon mini-FAQ  (Daniel Murphy, Mar 1998)  [Recommended reading]

[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