Cube Handling in Races

Forum Archive : Cube Handling in Races

Pip count percentage

From:   Jeff Mogath
Date:   25 February 2001
Subject:   Pip Count percentage

I understand that if you're more than twelve percent behind in the pip
count you should probably drop. How do you figure this percentage?
Any help is appreciated. Thanks


hi  writes:


If you are playing online usually there is a pip count displayed, so
if the pip count for you is 100 and you are more than 12 pips behind
you should drop (.12 x 100 = 12).  If your pip count is 60 and you are
8 pips behind you should drop (.12 x 60 = 8 rounded up).

If the pip count is not displayed, then you have to learn how to count
pips, and there are many ways to do that.  Look around online for the
various methods.  In Paul Magriel's "Backgammon" he recommends taking
if you are behind 10 pips or less in a 60 pip race, and 13 pips or
less in a 100 pip race.  How do you know how long a 60 pip or 100 pip
race is approximately? If all your men are in your inner board and
equally distributed, you are in a 60 pip race (15 men, average
position is on the 4pt-->15 x 4 = 60).  A 100 pip race is one in which
there are about 4 or 5 rolls before the bear off begins (average roll
of the dice is 8 pips, 5 x 8 = 40).

Gregg Cattanach  writes:

A slightly more accurate system goes like this.  (And the calculations
are easier).

Take the leader's pip count and multiply by 10%.  Then take that
number, subtract 2, and that's the pip difference for an initial
double.  Subtract 1 from the 10% number, and that's the difference for
a redouble.  Add 2 to the 10% number and that's the pip difference
where the opponent should pass.

This applies if both sides have similar high variance positions, (not
a lot of checkers piled up on the low points.)  This turns out to be
remarkably accurate for any pip count from around 65 up to any large
number.  And the math is easier :)  The 8%, 9%, 12% system
overestimates the differences necessary when you get up to 120 pips or
more, and underestimates it when you are down below 80 pips.

This 10%-2, 10%-1, 10%+2 system is based on long computer simulations
of the 'single-checker model'.

This method does require getting an accurate pip count for both sides.
I recommend Jack Kissane's Cluster Counting method:
Did you find the information in this article useful?          

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


Cube Handling in Races

Bower's modified Thorp count  (Chuck Bower, July 1997) 
Calculating winning chances  (Raccoon, Jan 2007) 
Calculating winning chances  (OpenWheel+, Nov 2005)  [GammOnLine forum]
Doubling formulas  (Michael J. Zehr, Jan 1995) 
Doubling in a long race  (Brian Sheppard, Feb 1998) 
EPC example  (adambulldog+, Jan 2011) 
EPC example: stack and straggler  (neilkaz+, Jan 2009) 
EPC examples: stack and straggler  (Carlo Melzi+, Dec 2008) 
Effective pipcount  (Douglas Zare, Sept 2003)  [GammOnLine forum]
Effective pipcount and type of position  (Douglas Zare, Jan 2004)  [GammOnLine forum]
Kleinman count  (Øystein Johansen+, Feb 2001) 
Kleinman count  (André Nicoulin, Sept 1998) 
Kleinman count  (Chuck Bower, Mar 1998)  [Recommended reading]
Lamford's race forumla  (Michael Schell, Aug 2001) 
N-roll vs n-roll bearoff  (David Rubin+, July 2008) 
N-roll vs n-roll bearoff  (Gregg Cattanach, Nov 2002) 
N-roll vs n-roll bearoff  (Chuck Bower+, Dec 1997) 
Near end of game  (Daniel Murphy, Mar 1997) 
Near end of game  (David Montgomery, Feb 1997) 
Near end of game  (Ron Karr, Feb 1997) 
One checker model  (Kit Woolsey+, Feb 1998) 
Pip count percentage  (Jeff Mogath+, Feb 2001) 
Pip-count formulas  (Tom Keith+, June 2004)  [GammOnLine forum]
Thorp count  (Chuck Bower, Jan 1997) 
Thorp count  (Simon Woodhead, Sept 1991) 
Thorp count questions  (Chuck Bower, Sept 1999) 
Value of a pip  (Tom Keith, June 2004) 
Ward's racing formula  (Marty Storer, Jan 1992) 
What's your favorite formula?  (Timothy Chow+, Aug 2012) 

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