RE: [Bug-gnubg] EPC (Trice) and other counts

[Ian Shaw]

Hi Adi,

1) EPC stands for "effective pip count", which is the average number of
rolls you need to bear off multiplied by the average pips per roll. The
information is derived from a database, but you can learn to estimate it
quite well.

The epc is therefore just a modified pip count. You can then use a
variety of formulas to help you decide the cube action. If both sides
have efficient racing positions then standard racing formulas such as
Trice's "Rule 62" work well. If one side is heavily stacked on the low
points then other formulas work better. The beauty of epc is that it
considers all things under a common framework founded on a sound
mathematical basis.

2) Certainly.

3) Personally, I prefer epc methods to Ward or Keith counts, to the
extent that I've forgotten how to use them. I feel Keith and Ward make
too much of crossovers.

The best information about the Trice count and epc methods are at
www.gammonvillage.com where Walter Trice's original articles appeared.
They are also contained in Walter's excellent book "Backgammon Boot
Camp". Douglas Zare's articles on races at Gammon Village also use epc. 


-- Ian Shaw


________________________________

        From: Adi Kadmon
        Sent: 13 November 2010 13:03
        To: address@hidden
        Subject: [Bug-gnubg] EPC (Trice) and other counts
        
        
        Hello all
         
        I'd like very much to have the following information:
         
        (1) What is GNUbg's formula for calculating "EPC"/"Trice count"
of bearoff positions?
         
        (2) Is that formula, or any approximation thereof, practically
usable by a human player during a real game?
         
        (3) Is the EPC/Trice count, if calculated precisely, actually
more "correct" than, for instance, Ward count or Keith count, for cube
decisions in bearoff positions?
         
         
        Thanks,
         
        -- Adi