Forum Archive : Terminology

"Thorp count"

From:   Stephen Turner
Address:   sret1@statslab.cam.ac.uk
Date:   21 June 1996
Subject:   Racing doubles (was Re: BG by Magriel)
Forum:   rec.games.backgammon
Google:   31CA6A4B.25DC@statslab.cam.ac.uk

SEM wrote:
> > Elsewhere their advice is wrong:
> > "In a long-running game, double if you lead by over 10% of your
> > pipcount. If this lead is over 15%, your opponent should concede."
> What is the correct version of this advice?

Roughly, 8% lead to double from centre, 9% to redouble, at most 12% behind
to take. (Incidentally, I'm always amazed that there is a working formula
which is a constant percentage of the pipcount). Short races and positions
with odd bearoff distributions may need modification, which can be done by
the Thorpe count and other specialised counts.

Before anyone asks, the Thorpe count is pipcount, plus 2 for each chequer
still on the board, minus 1 for each inner board point with any chequers
on, plus 1 for each chequer on the ace point. If the leader's count is over
30, he must then add 10%. The leader should double if his count is at most
2 greater than the trailer's, redouble if only 1 greater, and the trailer
should drop if the leader is 2 ahead. Got that?

At different match scores, you need to know your percentage winning chance.
Does anyone know a SIMPLE formula for that? (That doesn't rely on me having
to multiply by numbers like 73 over the board!)

Stephen R. E. Turner
  Stochastic Networks Group, Statistical Laboratory, University of
  Cambridge e-mail: sret1@cam.ac.uk  WWW:
  http://www.statslab.cam.ac.uk/~sret1/home.html "You may notice that your
  Customer Reference Number has changed" British Gas
Did you find the information in this article useful?          

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



Alphabet soup  (Tom Keith, Apr 2004)  [GammOnLine forum]
"Anchor and guard" position  (Chase+, Apr 2010) 
"Back game"  (Marty Storer, Jan 2004)  [GammOnLine forum]
"Baffle box"  (garyo+, Mar 2005)  [GammOnLine forum]
"Bagai position"  (Timothy Chow, Dec 2012)  [Long message]
"Banana split"  (Rich Munitz+, June 2011) 
"Banana split"  (Adam Stocks+, Sept 2004) 
"Beavers"  (Sander van Rijnswou, May 1999) 
"Beavers"  (Shuman Lloyd Lee, Aug 1991) 
"Blunder", "whopper"  (Raccoon+, July 2005)  [GammOnLine forum]
"Bot"  (Pit Bull+, Mar 2004) 
"Bronstein" clock setting  (rew+, Sept 2012) 
"Calcutta auction"  (Roland Scheicher+, Dec 2001) 
"Chouette"  (Roland Scheicher+, Mar 2002) 
"Cube provocation play"  (Chuck Bower+, Apr 2007)  [GammOnLine forum]
"Dance"  (William R. Tallmadge, May 1998) 
"Dropper"  (Robert D. Johnson, Sept 1996) 
"Duplication" and "diversification"  (Simon Woodhead, Nov 1991) 
"Equity"  (Gregg Cattanach, Aug 2000) 
"Equity"  (Gary Wong, Dec 1998) 
"Equity"  (Chuck Bower, Oct 1996) 
"Equity"  (Michael J. Zehr, Mar 1996) 
"Equity", "volatility", "claim", "market"  (Erik Gravgaard, June 1995) 
"Freeroll"  (montygram, Nov 2005) 
"Gammon price"  (Ron Karr, Aug 1996) 
"Gammon rate", "gammon price"  (David Montgomery, June 1995) 
"Gammon-go" (GG) and "gammon-save" (GS)  (Mary Hickey, Feb 2004)  [GammOnLine forum]
"Gammon-go" (GG) and "gammon-save" (GS)  (Marty Storer, Oct 2002)  [GammOnLine forum]
"Gammon-go" (GG)   (Chuck Bower, Jan 2004) 
"Golden point"  (Daniel Murphy, Dec 2004)  [GammOnLine forum]
"Holding game"  (Alan Webb+, Dec 1998) 
"In the box"  (Ken Bame+, Sept 2012) 
International phrase dictionary  (David Allen Sorensen, Sept 1997) 
"Joker"  (Richard Divdesman, Sept 1998) 
"Kamikaze play"  (Bill Patterson+, June 2011) 
"Kauder paradox"  (Carl Tait+, Nov 1995) 
"Latto paradox"  (Jean-Pierre Seiman+, July 2004) 
"Lose your market"  (Shuman Lloyd Lee+, Aug 1991) 
"MCV"  (Mislav Radica+, Oct 2009) 
"PRaT"  (Raccoon+, Jan 2007)  [GammOnLine forum]
"Phantom double hit"  (Marty Storer, May 2010) 
"Polish prime"  (Jason Lee+, Jan 2006)  [GammOnLine forum]
"Pure play"  (Daniel Murphy, Nov 2000) 
"Pure play"  (Casey Forrest+, Feb 1996) 
"Raccoon"  (Steven Keats, Feb 2011) 
"Root number"  (Ken Bame, June 2004)  [GammOnLine forum]
"Russian Bridges"  (leobueno+, Mar 2013) 
"Short play"  (AJ+, July 2012) 
"Speed board"  (Gregg Cattanach, June 2004) 
"Splot"  (mamabear, Apr 2007) 
"Squeeze", "trap play"  (Philippe Michel+, Feb 1997) 
"Suicide play"  (Brian Sheppard, Aug 1997) 
"Swing tournament"  (Carlo Melzi+, Mar 2006) 
"Table stakes"  (Carlo Melzi, Sept 2002) 
"Technical play"  (Adam Stocks+, July 2002) 
"Thematic"  (Beauregard+, Aug 2009) 
"Thorp count"  (Stephen Turner, June 1996) 
"Time," "timing," "checker," "dancing"  (Marty Storer, Apr 1992) 
Turkish names for rolls  (Lars Soezueer, Mar 1997) 
"Vigorish"  (Anthony R Wuersch, Feb 1995) 
"Volatility"  (Michael J. Zehr, June 1998) 
"Wash"  (Hardy Hübener+, Sept 2004) 
"Wash"  (Brian Sheppard, July 1997) 
"Weaver"  (Alan Webb+, May 2000) 
"Zone" of attack  (Matt Reklaitis+, Dec 2007)  [GammOnLine forum]

[GammOnLine forum]  From GammOnLine       [Long message]  Long message       [Recommended reading]  Recommended reading       [Recent addition]  Recent addition

  Book Suggestions
Computer Dice
Cube Handling
Cube Handling in Races
Extreme Gammon
Fun and frustration
GNU Backgammon
Luck versus Skill
Magazines & E-zines
Match Archives
Match Equities
Match Play
Match Play at 2-away/2-away
Opening Rolls
Pip Counting
Play Sites
Probability and Statistics
Source Code
Strategy--Bearing Off
Strategy--Checker play


Return to:  Backgammon Galore : Forum Archive Main Page