Cube Handling

Forum Archive : Cube Handling

With the Jacoby rule

From:   KL Gerber
Date:   20 November 2002
Subject:   cube considerations under Jacoby rule

I have played some money games with and without the Jacoby rule, and I
was wondering how the rule affects cube decisions.

It seems right to me that there will be more Double/Drops with the JR
than without the JR.  (Since there will be no NoDouble/Drops with the
cube at 1.)

But what about early doubles? Does the JR motivate more early
doubling...or am I missing the point?


Douglas Zare  writes:

There are a few situations in which there are correct doubles with the
Jacoby Rule that are not correct without the Jacoby Rule. Usually it does
not make much of a difference. Exchanges which leave you too good to
double are larger market losers with the Jacoby Rule, since you regret not
doubling more. However, most of the time, the value from being too good to
double is small compared to the difference between taking and passing the

The Kauder paradox is that with the Jacoby Rule, there are some positions
where it is correct to double even though your double will be beavered.
Generally, these would be positions with overwhelming gammon and
backgammon chances if you hit a direct shot, but in which you will be
doubled out if you miss. Latto's paradox is that there are positions which
are redoubles that are not initial doubles. This may happen if your
opponent is an underdog, but wins many more gammons than you do, so that
your opponent may end up too good to double without the Jacoby Rule.

Douglas Zare
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Cube Handling

Against a weaker opponent  (Kit Woolsey, July 1994) 
Closed board cube decisions  (Dan Pelton+, Jan 2009) 
Cube concepts  (Peter Bell, Aug 1995)  [Long message]
Early game blitzes  (kruidenbuiltje, Jan 2011) 
Early-late ratio  (Tom Keith, Sept 2003) 
Endgame close out: Michael's 432 rule  (Michael Bo Hansen+, Feb 1998)  [Recommended reading]
Endgame close out: Spleischft formula  (Simon Larsen, Sept 1999) 
Endgame closeout: win percentages  (David Rubin+, Oct 2010) 
Evaluating the position  (Daniel Murphy, Feb 2001) 
Evaluating the position  (Daniel Murphy, Mar 2000) 
How does rake affect cube actions?  (Paul Epstein+, Sept 2005) 
How to use the doubling cube  (Michael J. Zehr, Nov 1993) 
Liveliness of the cube  (Kit Woolsey, Apr 1997) 
PRAT--Position, Race, and Threats  (Alan Webb, Feb 2001) 
Playing your opponent  (Morris Pearl+, Jan 2002)  [GammOnLine forum]
References  (Chuck Bower, Nov 1997) 
Robertie's rule  (Chuck Bower, Sept 2006)  [GammOnLine forum]
Rough guidelines  (Michael J. Zehr, Dec 1993) 
Tells  (Tad Bright+, Nov 2003)  [GammOnLine forum]
The take/pass decision  (Otis+, Aug 2007) 
Too good to double  (Michael J. Zehr, May 1997) 
Too good to double--Janowski's formula  (Chuck Bower, Jan 1997) 
Value of an ace-point game  (Raccoon+, June 2006)  [GammOnLine forum]
Value of an ace-point game  (Øystein Johansen, Aug 2000) 
Volatility  (Chuck Bower, Oct 1998)  [Long message]
Volatility  (Kit Woolsey, Sept 1996) 
When to accept a double  (Daniel Murphy+, Feb 2001) 
When to beaver  (Walter Trice, Aug 1999) 
When to double  (Kit Woolsey, Nov 1994) 
With the Jacoby rule  (KL Gerber+, Nov 2002) 
With the Jacoby rule  (Gary Wong, Dec 1997) 
Woolsey's law  (PersianLord+, Mar 2008) 
Woolsey's law  (Kit Woolsey, Sept 1996) 
Words of wisdom  (Chris C., Dec 2003) 

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