Forum Archive :
Tom's site is the first place I go to find definitions:
"Jacoby Rule: [Named for Oswald Jacoby, who proposed the rule.] A
rule popular in money play which says that gammons and backgammons
count only as a single game if neither player has offered a double
during the game. The Jacoby rule is not used in match play. The rule
speeds up play by eliminating situations where a player avoids doubling
so he can play on for a gammon."
Is this definition accurate? I'll give a hint: what if there is an
Jacoby Rule (my wording):
The multipliers (x2 for gammon, x3 for backgammon) shall be used if and
A) the doubling cube has increased in value by any means, or
B) the doubling cube has been offered and accepted.
You must choose one of (A) or (B). Which one?
- Books by Paul Magriel (1976) and Lewis Deyong (1977) imply A.
- Books by Philip Martyn (1976), and Jim and Mary Zita Jacoby (1973) (son
and wife of Ozzie) say B.
The tiebreaker (and trump card?) 1969 book by John Crawford and Oswald
Jacoby (credited by all with the rule) says (in Chapter 16 ... Variations
"Some people play the Jacoby rule as long as there has been no regular
double (as opposed to automatic doubles); we prefer to play it only
when the cube is at 1."
OTOH, maybe Jacoby's wishes can/should be overridden by
Casper van der Tak writes:
Gammons and BGs don't count before the first cube turn. An automatic double
means that the cube starts on 2, 4, whatever, but it is not turned yet. I
did not check the formulation, but probably the Jacoby rule could be best
worded as that gammons and backgammons don't count with the cube in the
Sam Pottle writes:
B seems obvious to me, but I recognize that others may not agree.
Steve Mellen writes:
I think I need to know what they actually wrote before I know if there's an
I think most people would see (B) as the more natural answer. But if you
actually think about the purpose behind the Jacoby Rule -- which I might
paraphrase as "let's not waste a lot of time playing on for a gammon with
the cube on 1" -- I think (A) is the more logical answer. If someone can
suggest a different purpose for the Jacoby Rule that makes (B) the more
logical response, I'm all ears.
Chuck Bower writes:
As far as the definitions by Magriel and Deyong in their books, here is
verbatim what they say:
"Players can agree before the game begins that gammons and backgammons
will count only as 1 point if the cube has not been doubled by a player
during the course of the game."
"The Jacoby Rules prohibits either player from wining more than 1 point
in a game unless the cube has been turned."
It's far from obvious either of these even consider automatic doubles. I
interpreted the specific number '1' in each to indicate automatics would
negate the rule, but that might not be the proper interpretation,
particularly for Magriel's where he may have been referring to the
gammon/backgammon multiplier being 1. But for the most part I don't think
they recognized the ambiguity/confusion that I bring up.
Jacoby-Crawford (as quoted earlier) and Martyn explicitly mention automatic
doubles and how they affect the rule (and the two books take the opposite
view). Jim and Mary Zita say "... Unless a double has been made and
accepted, either player can concede a single game at any time."
Pragmatically, IMO, unless you know how your opponent interprets the rule
it should be discussed beforehand when you are playing automatics.
- Bearing off question (Colin Wiel+, July 2000)
- Can a beaver be dropped? (Robert-Jan Veldhuizen+, Mar 2006)
- Can a beaver be dropped? (Stein Kulseth, May 2000)
- Changing dice (Julian Hayward, Feb 1998)
- Checker shuffling (James Johnson+, June 2000)
- Gentleman's previlege (Daniel+, Sept 2005)
- Hit and run (Rich+, Jan 2000)
- "Illegal moves" rule (Chuck Bower+, May 2004)
- Illegal plays (Bob+, Aug 2002)
- Illegal plays (Marc Gray, Nov 1995)
- Illegal plays that can't be condoned (Matt Cohn-Geier+, Feb 2011)
- Is stalemate possible? (Jan Andrew Bloxham+, July 1995)
- Jacoby rule (Daniel Murphy, Dec 1997)
- Jacoby rule ambiguity? (Chuck Bower+, Mar 2011)
- Jacoby rule--Good or bad? (neilkaz+, May 2006)
- Legal roll (Sture Lifh+, July 2004)
- Legal roll (Gregg Cattanach, Oct 2001)
- Moving checkers unambiguously (Timothy Chow+, Oct 2009)
- Moving checkers with two hands (Michael Strato+, June 2000)
- Must a hit checker be placed on the bar? (Dani+, May 2006)
- Pick and pass and bearing off (SimonW+, Jan 2005)
- Play cubeless at 2away/2away? (Raccoon+, Oct 2005)
- Repairing an illegal play (Michael J. Zehr, Apr 1995)
- Resigning (Bob Lang+, Aug 2002)
- Rolling on wrong side of board (Ian Shaw+, Aug 2004)
- Rolling on wrong side of board (Kit Woolsey, Jan 1999)
- Rolling on wrong side of board (Kit Woolsey, Sept 1998)
- Rolling on wrong side of board (Bob Hoey, Apr 1998)
- Rolling too soon (TonyM+, Feb 2007)
- Rolling too soon (Stephen Turner, Feb 1998)
- Rolling too soon (James Grenier+, Sept 1996)
- Talking during play (EdmondT+, Dec 2000)
- Touch-move rule in backgammon? (Ken Bame+, Nov 2006)
- Touch-move rule in backgammon? (Austefjord+, May 2002)
- U.S. backgammon tournament rules (Butch Meese, Nov 1997)
- When do you give up your chance to double? (Paul Epstein+, July 2005)
- When is a move over? (JP White, May 2000)
- Overview (Daniel Murphy, Apr 2001)