Match Equities

 ME Table: Snowie

 From: Harald Retter Address: harald.retter@okay.net Date: 20 August 1998 Subject: Snowie match equity chart Forum: rec.games.backgammon Google: 6rhjv8\$lfs\$1@trader.ipf.de

```Snowie uses its own match equity table, based on a gammon
rate of 26%. I couldn't find those equities summarized in
a diagram, so I spent some minutes to create one. As I am
not willed to memorize more than that, I did it up to -9.
Here is the result:

You
need|  1*   1    2    3    4    5    6    7    8    9
----+--------------------------------------------------
1* | 50.0  --  51.5 68.5 69.5 81.3 81.9 88.8 89.1 93.3
1  |  --  50.0 68.5 75.1 82.0 84.3 89.1 90.8 93.6 95.0
2  | 48.5 31.5 50.0 60.4 68.5 75.3 81.0 85.1 88.5 90.9
3  | 31.5 24.9 39.6 50.0 57.8 65.3 71.7 76.8 81.2 84.6
4  | 30.5 18.0 31.5 42.2 50.0 57.9 64.6 70.3 75.2 79.4
5  | 18.7 15.7 24.7 34.7 42.1 50.0 56.8 62.8 68.1 72.9
6  | 18.1 10.9 19.0 28.3 35.4 43.2 50.0 56.3 61.9 67.1
7  | 11.2 09.2 14.9 23.2 29.7 37.2 43.7 50.0 55.6 61.0
8  | 10.9 06.4 11.5 18.8 24.8 31.9 38.1 44.4 50.0 55.5
9  | 06.7 05.0 09.1 15.4 20.6 27.1 32.9 39.0 44.5 50.0

*  = Post Crawford

While typing all those numbers, I was quite surprised how
similar they seemed to be to the Woolsey-table, I used to
work with (and actually still do). If my memory is right,
Kits tables where computed assuming a gammon rate of 20%.
Quite a difference, but the tables do not seem to reflect
on it much. So I created a second diagramm to display the
differences between the two versions. I took the numbers,
which are printed in "Cubes and Gammons..." by Ortega and
Kleinman and subtracted them from Snowie-values:

YON

YN |  1*   1    2    3    4    5    6    7    8    9
----+--------------------------------------------------
1*|  #    --   #    #    #    #    #    #    #    #
1 |  --   0   -1.5 +0.1 -1.1 -0.9 -1.1 -0.5 -0.6 -0.1
2 |  #   +1.5  0   +0.6 +0.7 +0.5 +0.2 +0.3 +0.5 +0.1
3 |  #   -0.1 -0.6  0   +1.5 -0.5 +0.2 +0.4 +0.7 +0.2
4 |  #   +1.1 -0.7 -1.5  0   -0.1 +0.2  0   -0.2  0
5 |  #   +0.9 -0.5 +0.5 +0.1  0   -0.5 -0.5 -0.3 -0.4
6 |  #   +1.1 -0.2 -0.2 -0.2 +0.5  0   +0.1 -0.4 -0.2
7 |  #   +0.5 -0.3 -0.4  0   +0.5 -0.1  0   -0.6 -0.3
8 |  #   +0.6 -0.5 -0.7 +0.2 +0.3 +0.4 +0.6  0   +0.2
9 |  #   +0.1 -0.1 -0.2  0   +0.4 +0.2 +0.3 -0.2  0

# = only Snowie-data available

Oh, how nice, only four matchscores (-1-2/-1-4/-1-6/-3-4)
differ more than 1%point, the largest is 1.5%points. Once
these figures should get "accepted", there is not as much
to relearn as I feared. Most discrepancies appear at -1-T
(T = points to go for Trailer). As expected the increased
gammon rate favours the Trailer at these scores, with him
only having usage of those extra-points.

I am confused by the result for -4-3. A doubled gammon at
this score should be a big shot for the trailer,  winning
the match exactly outright.  His matchequity should raise
assuming a larger gammon rate. Food for thought,  who has
an idea?

Regards, Harald Retter
```

### Match Equities

Constructing a match equity table  (Walter Trice, Apr 2000)
Does it matter which match equity table you use?  (Klaus Evers+, Nov 2005)
Does it matter which match equity table you use?  (Achim Mueller+, Dec 2003)
Does it matter which match equity table you use?  (Chuck Bower+, Sept 2001)
ME Table: Big Brother  (Peter Fankhauser, July 1996)
ME Table: Dunstan  (Ian Dunstan+, Aug 2004)
ME Table: Escoffery  (David Escoffery, Nov 1991)
ME Table: Friedman  (Elliott C Winslow, Oct 1991)
ME Table: Kazaross  (Neil Kazaross, Dec 2003)
ME Table: Kazaross-XG2  (neilkaz, Aug 2011)
ME Table: Rockwell-Kazaross  (Chuck Bower+, June 2010)
ME Table: Snowie  (Chase, Apr 2002)
ME Table: Snowie  (Harald Retter, Aug 1998)
ME Table: Woolsey  (Raccoon, Apr 2006)
ME Table: Woolsey  (Kit Woolsey, May 1994)
ME Table: Woolsey  (William R. Tallmadge, Jan 1994)
ME Table: Zadeh  (Jørn Thyssen, Mar 2004)
ME Table: Zorba  (Robert-Jan Veldhuizen+, Dec 2003)
ME at 1-away/2-away (crawford)  (Fabrice Liardet+, Nov 2007)
ME at 1-away/2-away (crawford)  (Ian Shaw+, Apr 2003)
Match equities--an alternate view  (Durf Freund, Oct 1994)
Neil's new numbers  (neilkaz, Aug 2011)
Neil's numbers  (Kit Woolsey+, Oct 1994)
On calculating match equity tables  (Neil Kazaross, July 2004)
Turner formula  (Gregg Cattanach, Feb 2003)
Turner formula  (Stephen Turner, June 1994)
Using a match equity table  (Michael J. Zehr, June 1992)
Value of free drop  (Neil Kazaross, Oct 2002)
Which match equity table is best?  (Martin Krainer+, Oct 2003)
Which match equity table is best?  (Ian Shaw+, Dec 2001)
Why use a match equity table?  (Kit Woolsey, Feb 1999)
Worth memorizing?  (Alef Rosenbaum+, Feb 2003)