Cube Handling

Forum Archive : Cube Handling

Evaluating the position

From:   Daniel Murphy
Date:   3 February 2001
Subject:   Re: How to analyze a cube action?

> A question on evaluating positions -- I've read all about how I should
> double if I have corrected winning chances of 75% and I should take if I
> have 25% chance. But I've never really seen anything on how to know when
> I'm there.
> I've read some books, most of which show a position, say "Cube action?"
> and then give a very vague summation of one side's structure .vs. the
> other side's deceivingly strong-looking position and then just
> pontifically says, "Black should double, white has a close take." How do
> you get to that point?

Kit Woolsey made up a helpful and simple rule: If you look at a
position and you're not sure the other side should take, then you MUST
double. If that helps you, great. If your game's a little more
sophisticated than that, also great

But I've tried to explain this rule to some novice players who just
say: Take? Drop? How the hell should I know?

So, to keep it very simple, your first goal in analyzing a position is
to answer this question: Who's winning?

And then try for a little more detail in your answer: are you winning
just a little, winning by a lot? Do you have a "can't lose" position?
Do you threaten to improve so much your opponent will wish he's never
seen a cube?

And here's your thinking structure:

Is there still contact between your opposing armies of checkers? If
not, you've got a simple race. Count the pips. If you lead by about
9%, double. 10%, redouble.

(If you've counted pips once and decide not to double, remember the
numbers. Subtract from that pipcount with each roll until you reach a
count that seems like a double. That way, you shouldn't have to
tediously count pips more than once in a game.)

If there is still contact, you need to do two things. The first is:
compare positions. Who's got more checkers back? Who's got the better
anchor? Who's got the better prime? Who's got the better flexibility
to turn a good position into a great one? Or the awkward position that
threatens to get worse? Who's got many rolls that do good things?
Who's relying on a miracle? Who's theatening to turn a contact
position into a no contact race? And who's the favorite if that

The second thing is: figure out if your position threatens to improve
so much that -- if you're successful -- your opponent wouldn't dream
of taking a cube. This is tricky: a lot of novices see a couple of
good numbers coming and turn the cube. Optimists. In backgammon it's
good to be an optimist but things don't always go our way. So, another
and often helpful way of thinking about this is: If you have several
numbers that will give you an overwhelming position, and most of the
the rest of the numbers leave you no worse than even, then you
probably have a double.

This may seem unsophisticated. I haven't even mentioned "math." But it
works. And believe me, if you can ask and answer the basic question:
who's winning? -- or even just consistently remember to ASK -- you're
a lot farther along than a lot of your opponents.

Daniel Murphy, Raccoon on FIBS, GamesGrid
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Cube Handling

Against a weaker opponent  (Kit Woolsey, July 1994) 
Closed board cube decisions  (Dan Pelton+, Jan 2009) 
Cube concepts  (Peter Bell, Aug 1995)  [Long message]
Early game blitzes  (kruidenbuiltje, Jan 2011) 
Early-late ratio  (Tom Keith, Sept 2003) 
Endgame close out: Michael's 432 rule  (Michael Bo Hansen+, Feb 1998)  [Recommended reading]
Endgame close out: Spleischft formula  (Simon Larsen, Sept 1999) 
Endgame closeout: win percentages  (David Rubin+, Oct 2010) 
Evaluating the position  (Daniel Murphy, Feb 2001) 
Evaluating the position  (Daniel Murphy, Mar 2000) 
How does rake affect cube actions?  (Paul Epstein+, Sept 2005) 
How to use the doubling cube  (Michael J. Zehr, Nov 1993) 
Liveliness of the cube  (Kit Woolsey, Apr 1997) 
PRAT--Position, Race, and Threats  (Alan Webb, Feb 2001) 
Playing your opponent  (Morris Pearl+, Jan 2002)  [GammOnLine forum]
References  (Chuck Bower, Nov 1997) 
Robertie's rule  (Chuck Bower, Sept 2006)  [GammOnLine forum]
Rough guidelines  (Michael J. Zehr, Dec 1993) 
Tells  (Tad Bright+, Nov 2003)  [GammOnLine forum]
The take/pass decision  (Otis+, Aug 2007) 
Too good to double  (Michael J. Zehr, May 1997) 
Too good to double--Janowski's formula  (Chuck Bower, Jan 1997) 
Value of an ace-point game  (Raccoon+, June 2006)  [GammOnLine forum]
Value of an ace-point game  (Øystein Johansen, Aug 2000) 
Volatility  (Chuck Bower, Oct 1998)  [Long message]
Volatility  (Kit Woolsey, Sept 1996) 
When to accept a double  (Daniel Murphy+, Feb 2001) 
When to beaver  (Walter Trice, Aug 1999) 
When to double  (Kit Woolsey, Nov 1994) 
With the Jacoby rule  (KL Gerber+, Nov 2002) 
With the Jacoby rule  (Gary Wong, Dec 1997) 
Woolsey's law  (PersianLord+, Mar 2008) 
Woolsey's law  (Kit Woolsey, Sept 1996) 
Words of wisdom  (Chris C., Dec 2003) 

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