Cube Handling in Races

 Calculating winning chances

 From: Raccoon Address: racgammon@yahoo.com Date: 31 January 2007 Subject: Re: Racing in matches Forum: rec.games.backgammon Google: 1170257096.323749.323000@q2g2000cwa.googlegroups.com

```> > Is there a handy set of reasonably accurate guidelines which can be
> > applied to match play?
>
> Walter Trice suggests interpolation which is pretty simple to use over
> the board.

I think the following table is useful, memorizably simple and rather
accurate:

Your cubeless winning chances when you are on roll

50   60   70   80   90   100
-4 pips     50%  50%  50%  50%  50%  50%
0 pips     62%  61%  60%  60%  59%  58%
7 pips     78%
8 pips          78%
9 pips               78%
10 pips                    78%
11 pips                         78%
12 pips                              78%

These percentages are not *exactly* right. They've been rounded to 2
digits, of course, and sometimes rounded down instead of up to create
an easily memorizable and still quite accurate pattern. A deficit of 4
pips is very close to 50% GWC over an even broader range of pipcounts
than the table shows. The percentages for even races are off by no
more than 0.6%. And 78% is the best single two-digit approximation of
a 10% (rounded down, i.e., no rounding for these pipcounts) plus 2
```

### 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)
Doubling formulas  (Michael J. Zehr, Jan 1995)
Doubling in a long race  (Brian Sheppard, Feb 1998)
EPC example: stack and straggler  (neilkaz+, Jan 2009)
EPC examples: stack and straggler  (Carlo Melzi+, Dec 2008)
Effective pipcount  (Douglas Zare, Sept 2003)
Effective pipcount and type of position  (Douglas Zare, Jan 2004)
Kleinman count  (Øystein Johansen+, Feb 2001)
Kleinman count  (André Nicoulin, Sept 1998)
Kleinman count  (Chuck Bower, Mar 1998)
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)
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)