Match Play

Forum Archive : Match Play

 
Delayed mandatory double

From:   Donald Kahn
Address:   donaldk@alpin.or.at
Date:   24 December 1997
Subject:   Re: Post-Crawford Strategy
Forum:   rec.games.backgammon
Google:   34a3306a.58404606@news.salzburg.co.at

Hank Youngerman wrote:
> Playing a FIBS match against a player with a decent rating, I took a
> 4-1 lead in a match to 5.  I lost the next (Crawford) game.  In the
> following game, my opponent did not double until about the 5th or 6th
> roll.  My guestimate is that his winning chances at that point were in
> the 60-65% range - clearly a take of course.  I made a statement that
> "It always surprises me how often good players (and myself too) forget
> to double right away post-Crawford."  My opponent said that he
> intentionally waited, in the hope that he would get a free point (i.e.
> his position would be strong enough to induce a drop.)
>
> My belief is that this cannot possibly be correct strategy.  First, it
> just FEELS wrong.  On a more analytical level, unless you think your
> opponent's judgment is very poor and that he will take a clear drop,
> in effect you are saying "I want to maneuver you into a position where
> you have a drop.  But then, even though I would like to force you to
> take such a position, I want you to drop it anyway.  (Since I could
> "force" you to take in such a position by making a no-cost double
> earlier before my position got this strong.)"
>
> Who's right, him or me?

Many of the very best players on the tournament circuit do this.  Paul
Magriel (x-22) calls it "the trick".  The idea is this: the trailer
benefits greatly if he can steal a point here - he is then an
even-money bet in the match.

He knows you will take if he doubles at the first opportunity.  If he
waits, he is giving you a chance to make a mistake.  Mainly this will
happen when *there is some gammon danger*.  Now you have something to
think about, don't you?

The simple arithmetic says you should take *unless* your chances of
losing a gammon are greater than your chances of winning.  Are you
sure you can judge this accurately in every case?  If so, hats off to
you!!

If you take, he is no worse off than having doubled at the first
opportunity.  If you pass and passing is an error, he benefits.  If
you take and *that* was an error, he benefits.

Looks like a 100% proposition for him to wait.

deekay

Kit Woolsey  writes:

If the leader in the match fully understands the situation, then this
ploy obviously can gain nothing.  But if he doesn't, the gain can be
considerable.

Let's suppose the trailer waits, and the game develops into a straight
race where the trailer is 90% to win (gammons not possible).  He now
doubles.  Would you take or pass if you were the leader?  If your answer
was that you would pass, you have fallen into his trap.  Now he only has
to win one game to win the match (since NEXT game he will double on the
opening roll), while if you take he has to win both this game and the next
game.

Think this is so obvious that nobody will fall for it?  Think again. Using
this ploy I have often stolen a vital point, and not just against
beginners.  I have seen several quite competent players fall into this
trap.

Kit
 
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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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