Terminology

Forum Archive : Terminology

 
"Squeeze", "trap play"

From:   Philippe Michel
Address:   michel@thomson-lcr.fr
Date:   21 February 1997
Subject:   Trap play questions
Forum:   rec.games.backgammon
Google:   E5yAqK.AMH@news.thomson-lcr.fr

+24-23-22-21-20-19-+---+18-17-16-15-14-13-+
| 8  O             |   |          X  X    |
| O  O             |   |                  |
| O  O             |   |                  |
| O  O             |   |                  |
| O  O             |   |                  |
|                  |   |                  |
|                  |   |                  |
|                  |   |                  |
|                  |   |                  |
|                  |   |                  |
|    O  X  X  X  X |   | X  X             | 2
|    O  X  X  X  X |   | X  X     X       |
+-1--2--3--4--5--6-+---+-7--8--9-10-11-12-+

   Score: O 5 away, X 3 away ; X on roll

What is the correct cube action ?

If X tries to close the 2 back men out, should he break the 8 point
only or the 7 and 8?

Kit Woolsey  writes:

> What is the correct cube action ?

If X doubles, O's takepoint is 15%.  I don't think O will win that
often (although it might be closer than one might think), so O should
pass.

Should X play on?  Not clear.  X's gammon chances aren't great, but
they do exist.  The downside isn't very great.  The only way X could
really get into trouble fast is if he goes for the squeeze and O rolls
the killing doubles immediately.  I think I would take a roll, and
then if I didn't immediately get a successful squeeze going I would
cash.

> If X tries to close the 2 back men out, should he break the 8 point
> only or the 7 and 8 ?

Neither!  The best squeeze technique here is to break the 7 point and
hold the 8 point.  This gains big if O rolls 5-1, and limits how far O
can escape if O is forced to run with one checker.

Brian Sheppard  writes:

Why not roll? After all, nothing dramatic will happen next turn.

I did an interactive rollout against JF Level 7, since JF Level 6
badly mishandles X's position. X wins 84.6%, with 24.9% gammons
against O's 15.4% wins and negligible gammons. X's cubeless equity
is 0.935, with a standard deviation of 0.028. It is hard to be
certain that X's equity when owning the cube exceed 1.000, but my
gut feel is that it does, since it seemed to me that about half
of X's losses occurred after X would have doubled O out of the game.

The tactics that X should pursue are as follows:

    0) Keep the 2 men back on the 14 ad 15 points unless forced
    to move off. (JF Level 6 moves these men.) If you are forced
    to move one of those men, prefer to move the 15 point, since
    keeping the 14 point man allows you to win if O rolls 6-6.

    1) Break the 7 or 8 points at the first opportunity. Give
    preference to breaking the 8-point first, since it is easier
    to break the 7 later.

    2) Break the other point at the first opportunity. JF Level 6
    will keep both outside points.

    3) Use the blot on the 10 point as spare timing in case you have a
    roll that doesn't break the outside priming points. Note that if
    the opponent had a board threat then you would not be able to
    use this resource, since an outfield hit could be fatal.

    4) Hit all blots. Given the choice between closing out with one
    man on the bar and having a 5-point board with 2 men, you should
    choose to hit 2 men, even if it means leaving a blot. Again, the
    opponent's crunched board makes this tactic possible.

    5) Do not be afraid to slot the ace point, or cover it, if
    that will allow you to keep the hitting checkers in place. After
    all, you intend to cover that point anyway!

    6) Double O out if you are forced to move the back checkers.
    By that point there is little hope of winning a gammon.

X's ownership of the cube is very important, as is O's weak board.
Without those two factors the tactics outlined above would not work.

For this tournament situation you should cash, possibly after letting
a roll or two go by, just to see how things develop. If any
awkwardness appears, however, you should cash. If the score were
reversed, then playing on would be clear.

Brian

tptron  writes:

I think the trap (forcing him to leave one man back and hit it) in
this case is a much better plan then the squeeze. It of course,
depends on the rolls. If he can force hin to break that point he can
hopefully close the table and have a chance (although unlikly) at the
gammon.

Brian Sheppard  writes:

Tom Keith asks:
> Squeeze?

The equivalent of exploiting zugzwang in chess: to take advantage
of the opponent's compulsion to move any playable roll.

> Trap play?

A trap play is a deliberate attempt to squeeze an opponent off of
his anchor, so that the trapper can close out any blots thereby
exposed and win a gammon.
 
Did you find the information in this article useful?          

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

 

Terminology

Alphabet soup  (Tom Keith, Apr 2004)  [GammOnLine forum]
"Anchor and guard" position  (Chase+, Apr 2010) 
"Back game"  (Marty Storer, Jan 2004)  [GammOnLine forum]
"Baffle box"  (garyo+, Mar 2005)  [GammOnLine forum]
"Bagai position"  (Timothy Chow, Dec 2012)  [Long message]
"Banana split"  (Rich Munitz+, June 2011) 
"Banana split"  (Adam Stocks+, Sept 2004) 
"Beavers"  (Sander van Rijnswou, May 1999) 
"Beavers"  (Shuman Lloyd Lee, Aug 1991) 
"Blunder", "whopper"  (Raccoon+, July 2005)  [GammOnLine forum]
"Bot"  (Pit Bull+, Mar 2004) 
"Bronstein" clock setting  (rew+, Sept 2012) 
"Calcutta auction"  (Roland Scheicher+, Dec 2001) 
"Chouette"  (Roland Scheicher+, Mar 2002) 
"Cube provocation play"  (Chuck Bower+, Apr 2007)  [GammOnLine forum]
"Dance"  (William R. Tallmadge, May 1998) 
"Dropper"  (Robert D. Johnson, Sept 1996) 
"Duplication" and "diversification"  (Simon Woodhead, Nov 1991) 
"Equity"  (Gregg Cattanach, Aug 2000) 
"Equity"  (Gary Wong, Dec 1998) 
"Equity"  (Chuck Bower, Oct 1996) 
"Equity"  (Michael J. Zehr, Mar 1996) 
"Equity", "volatility", "claim", "market"  (Erik Gravgaard, June 1995) 
"Freeroll"  (montygram, Nov 2005) 
"Gammon price"  (Ron Karr, Aug 1996) 
"Gammon rate", "gammon price"  (David Montgomery, June 1995) 
"Gammon-go" (GG) and "gammon-save" (GS)  (Mary Hickey, Feb 2004)  [GammOnLine forum]
"Gammon-go" (GG) and "gammon-save" (GS)  (Marty Storer, Oct 2002)  [GammOnLine forum]
"Gammon-go" (GG)   (Chuck Bower, Jan 2004) 
"Golden point"  (Daniel Murphy, Dec 2004)  [GammOnLine forum]
"Holding game"  (Alan Webb+, Dec 1998) 
"In the box"  (Ken Bame+, Sept 2012) 
International phrase dictionary  (David Allen Sorensen, Sept 1997) 
"Joker"  (Richard Divdesman, Sept 1998) 
"Kamikaze play"  (Bill Patterson+, June 2011) 
"Kauder paradox"  (Carl Tait+, Nov 1995) 
"Latto paradox"  (Jean-Pierre Seiman+, July 2004) 
"Lose your market"  (Shuman Lloyd Lee+, Aug 1991) 
"MCV"  (Mislav Radica+, Oct 2009) 
"PRaT"  (Raccoon+, Jan 2007)  [GammOnLine forum]
"Phantom double hit"  (Marty Storer, May 2010) 
"Polish prime"  (Jason Lee+, Jan 2006)  [GammOnLine forum]
"Pure play"  (Daniel Murphy, Nov 2000) 
"Pure play"  (Casey Forrest+, Feb 1996) 
"Raccoon"  (Steven Keats, Feb 2011) 
"Root number"  (Ken Bame, June 2004)  [GammOnLine forum]
"Russian Bridges"  (leobueno+, Mar 2013) 
"Short play"  (AJ+, July 2012) 
"Speed board"  (Gregg Cattanach, June 2004) 
"Splot"  (mamabear, Apr 2007) 
"Squeeze", "trap play"  (Philippe Michel+, Feb 1997) 
"Suicide play"  (Brian Sheppard, Aug 1997) 
"Swing tournament"  (Carlo Melzi+, Mar 2006) 
"Table stakes"  (Carlo Melzi, Sept 2002) 
"Technical play"  (Adam Stocks+, July 2002) 
"Thematic"  (Beauregard+, Aug 2009) 
"Thorp count"  (Stephen Turner, June 1996) 
"Time," "timing," "checker," "dancing"  (Marty Storer, Apr 1992) 
Turkish names for rolls  (Lars Soezueer, Mar 1997) 
"Vigorish"  (Anthony R Wuersch, Feb 1995) 
"Volatility"  (Michael J. Zehr, June 1998) 
"Wash"  (Hardy Hübener+, Sept 2004) 
"Wash"  (Brian Sheppard, July 1997) 
"Weaver"  (Alan Webb+, May 2000) 
"Zone" of attack  (Matt Reklaitis+, Dec 2007)  [GammOnLine forum]

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