Match Play

Forum Archive : Match Play

Going for gammon when opp has free drop

From:   Kit Woolsey
Date:   1 April 1995
Subject:   Re: -2:-1 post-crawford doubling strategy

Igor Sheyn wrote:
> I was playing a match yesturday and encountered following
> situation. It was, as subject indicates, -2:-1 post-crawford. I opened
> with 3-1, my opponent rolled 6-4 and misplayed it 24/14. After a short
> thinking process I decided not to double. I figured he has an easy
> drop. I have a number of huge rolls after which I am stuck to play for
> gammon, using Walter's terminology. He's unlikely to become a favorite
> after upcoming roll exchange, which would make me wish I had cashed. I
> figured if there exists a situation where it's better hold the cube
> trailing in -1:-2 post-crawford, then it must be the case here. Of
> course after correct play 24/18, 13/9, or EVEN 8/2, 6/2, I must
> double. THe basic reasoning is that by cashing I stand at 50% for
> match, while playing on at least for 1 roll I am a game, hence a
> match, favorite.
> Any valuable insights on this situations out there?

I have wondered about this for some time.  The general concept is that if
you are very unlikely to "gain your market" (that is, after the next you
roll he rolls sequence your opponent now has a take), then it is probably
correct to play for a gammon.  This thought process should be applied for
any position where you are considering playing for a gammon.  It may be
correct to play on even with a low gammon probability, if your chances of
gaining your market are zero or very small.

In this case, your opponent's take point is not the usual 25% but 50%!
This creates the unusual situation that if you are almost certain to be
the favorite after the next exchange, it is correct to play on for the
gammon.  Of course the situation will have to be reassessed after every
roll (which is always the case when playing for a gammon), but it is
quite possibly correct to play on.

I have done some study of the sequence you roll 3-1, he rolls 6-2
(probably the most favorable start for the player winning the opening
roll).  My studies have shown that it is very unlikely for you to be the
underdog after the next exchange (and if you are the underdog it is
usually by a very small amount so you won't have cost much equity by
waiting).  Since gammons are possible and it is certainly reasonable to
get one (and remain strong enough all the way through to continue to
justify playing on), it appears that it is correct to wait.  My guess
would be that in Igor's example it is also correct to wait.

This is all in theory.  In practice it is almost certainly correct to
double anyway.  The reason is that your opponent may not fully understand
the free drop concept, so he may make a mistake and take.  Only if I were
sure my opponent would not take the double would I even consider
waiting.  Note that this is consistent with normal playing for the gammon
decisions -- if there is any possibility that your opponent might take it
is definitely correct to double rather than play for the gammon.

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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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