Match Play

Forum Archive : Match Play

Delayed mandatory double

From:   tem_sat
Date:   13 October 2010
Subject:   Delayed Mandatory Double
Forum: Forums

From a Nations Cup match today. This reminded me of Matt's most recent (and
excellent) GV article about prime jumping:

     Score:  X is 3-away, O is 1-away

      12  11  10   9   8   7       6   5   4   3   2   1
     |                       |   |     X   X   X   X   X |
     |                       |   |     X   X   X   X   X |
     |                       |   |             X   X   X |
     |                       | O |                       |
     |                       | O |                       |   X on roll.
     |                       |   |                       |   Cube action?
     |                       |   |                       |
     |                       |   |                       |
     |                     O |   | O                     |
     |                 O   O |   | O   O   O             |
     | O           X   O   O |   | O   O   O       X     |
      13  14  15  16  17  18      19  20  21  22  23  24

Rich Munitz  writes:

It is surprising how many people don't have a clue what the take point is
at a no-free-drop score.  Quite simply, it is the point at which you lose
more gammons than you win games.

Who's winning here?  X must throw a 1 and a 6 before O throws a 6 and a 6.
That's about the same. X might hit the other O checker and buy more time.
However, X loses the timing battle when both players fail to perform
indefinitely. X is on roll and, given that everything else looks close,
being on roll may give X the edge.

So if X is winning say 55% here (O winning 45%), does X win a gammon 45 out
of those 55 times (about 80% of his wins)?  No way.  The open 6 point will
see to that and some of X's wins will be scrambling home after yellow

Double, take.

Carlo Melzi  writes:

I am the player that was tricked yesterday into a pass.  No excuse, I just
grossly overestimated single and gammon wins for my opponent, even though I
know free take scores pretty well and delay doubling myself as well.

Stanley Richards  writes:

OTB I would have also incorrectly passed this cube. It is such an atypical
backgammon position that my ability to estimate gammon losses would not be
as accurate as Rich's estimate. I would probably conclude that I know that
there are many gammons and I am not sure if the amount is greater than my
wins, so I better pass this.

I rarely encounter a position where my opponent has to roll a 1 and then
jump a prime.  And I have two checkers on the bar, his 6 point open, and
another blot.  This is a rarity where I have no reference positions.  It is
impressive that Rich could analyze this problem.

Rich Munitz  writes:

There is an easy and psychologically satisfying way to handle these
situations:  If there's any real uncertainty on the decision, just take.

You'll be no worse off than if your opponent had simply doubled on their
first opportunity. You don't give them the potential satisfaction of having
profited by waiting to double. And it is the only decision possible unless
your opponent has also made a cube error by waiting too long to double. At
least then if you incorrectly take, you're in good company.
Did you find the information in this article useful?          

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


Match Play

1-away/1-away: advice from Bernhard Kaiser  (Darse Billings, July 1995)  [Long message] [Recommended reading]
1-away/1-away: advice from Stick  (Stick+, Mar 2007)  [GammOnLine forum]
1-away/1-away: and similar scores  (Lou Poppler, Aug 1995) 
2-away/3-away: playing for gammon  (Tom Keith, Feb 1996) 
2-away/4-away: Neil's rule of 80  (Neil Kazaross, June 2004)  [GammOnLine forum]
2-away/4-away: cube strategy  (Tom Keith, Dec 1996) 
2-away/4-away: practical issues  (Mark Damish, Jan 1996) 
2-away/4-away: trailer's initial double  (Kit Woolsey, Jan 1996) 
3-away/4-away: opponent's recube  (William C. Bitting+, Feb 1997)  [Long message]
3-away/4-away: racing cube  (Bill Calton+, Nov 2012) 
3-away/4-away: tricky cube decision  (Kit Woolsey+, July 1994) 
3-away/4-away: what's the correct equity?  (Tom Keith, Sept 1997) 
4-away/4-away: take/drop point  (Gary Wong, Oct 1997) 
5-away/11-away: redouble to 8  (Gavin Anderson, Oct 1998) 
7-away/11-away: volatile recube decision  (Kit Woolsey, May 1997) 
Both too good and not good enough to double  (Paul Epstein+, Sept 2007) 
Comparing 2-away/3-away and 2-away/4-away  (Douglas Zare, Mar 2002) 
Crawford rule  (Chuck Bower, May 1998) 
Crawford rule  (Kit Woolsey, Mar 1997) 
Crawford rule--Why just one game?  (Walter Trice, Jan 2000) 
Crawford rule--history  (Michael Strato, Jan 2001) 
Delayed mandatory double  (tem_sat+, Oct 2010) 
Delayed mandatory double  (Donald Kahn+, Dec 1997)  [Recommended reading]
Doubling when facing a gammon loss  (Kit Woolsey, Jan 1999) 
Doubling when opponent is 2-away  (David Montgomery, Dec 1997) 
Doubling when you're an underdog  (Stein Kulseth, Dec 1997) 
Doubling window with gammons  (Jason Lee+, Jan 2009) 
Free drop  (Ian Shaw, May 1999) 
Free drop  (Willis Elias+, Oct 1994) 
Gammonless takepoint formula  (Adam Stocks, June 2002) 
Going for gammon when opp has free drop  (Kit Woolsey, Jan 1998) 
Going for gammon when opp has free drop  (Kit Woolsey, Apr 1995) 
Holland rule  (Neil Kazaross, Apr 2010) 
Holland rule  (Kit Woolsey, Dec 1994) 
Leading 2-away with good gammon chances  (Douglas Zare, Feb 2004)  [GammOnLine forum]
Match play 101  (Max Urban+, Oct 2009) 
Matches to a set number of games  (Tom Keith+, Oct 1998) 
Playing when opponent has free drop  (Gilles Baudrillard+, Dec 1996) 
Post-crawford doubling  (Scott Steiner+, Feb 2004) 
Post-crawford doubling  (Maik Stiebler+, Dec 2002) 
Post-crawford doubling  (Gus+, Sept 2002) 
Post-crawford mistakes  (Rob Adams, Sept 2007)  [GammOnLine forum]
Post-crawford/2-away: too good to double  (Robert-Jan Veldhuizen, July 2004) 
Slotting when opponent has free drop  (onur alan+, Apr 2013) 
Take points  (fiore+, Feb 2005)  [GammOnLine forum]
Tips to improve cube handling  (Lucky Jim+, Jan 2010) 
When to free drop  (Dan Pelton+, Oct 2006) 
When to free drop  (Tom Keith+, July 2005)  [GammOnLine forum]
When to free drop  (Gregg Cattanach, Dec 2004)  [GammOnLine forum]
When to free drop  (Kit Woolsey, Feb 1998) 
When to free drop  (Chuck Bower, Jan 1998) 
Which format most favors the favorite?  (Daniel Murphy+, Jan 2006)  [GammOnLine forum]

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