Propositions

 Opening 11 vs. Owning the cube

 From: Bob Ebbeler Address: rebbeler@bellsouth.net Date: 20 August 1999 Subject: Re: Double on double 1 ? Forum: rec.games.backgammon Google: NCov3.441\$dO3.8557@news4.mia

```> If you throw a double one and take the 5 and the 7 point you are
> (1) Blocking your opponent (2) 2 points away from setting a prime
> (3) giving yourself good time to create a hard anchor (4) giving
> youself a good block to help move down pieces from the 13 point.
> You are at a clear advantage in the game.
>
> It is my *tactical* decision to double. Please advise me if this is
> the ramblings of a misguided idiot.

One of my earliest, expensive lessons was over the issue you raised. I
wound up playing a proposition with another player wherein I started with
1-1 and he had the doubling cube on his side at 2. This was, and probably
still is, a time honored proposition and I will, hopefully, save you the
expense of learning the lesson I learned.

The guy who has the cube CRUSHES the guy who starts with 1-1.

NIHILIST
```

 Paul Tanenbaum  writes: ``` Bob, a backgammon hustler you aren't. The idea is to recoup the cost of your lesson at somebody else's expense. What was the equity for the cube-holder (assume at the 2-level)? Presumably you played it {6/5(2), 8/7(2)}. However, I don't like giving the indirect shot at the blot, so I would try {6/5(3), 24/23}. Has this alternative been rolled out? Probably not enough to make a difference in the prop, though. ```

 Daniel Murphy  writes: ```This proposition illustrates the value of cube possession. Early double aces is usually a fine number, and played 8/7(2) 6/5(2) on the very first roll of the game is enough to make you a 55-60% favorite straight off, but you forfeit your entire advantage if you have to give your opponent the cube before you move! I read "CRUSHES" to mean "solid favorite," and like Bob's hustler, I'd also happily let my opponent start with 11 in exchange for cube possession. A too-quick JF level 5 rollout (1296 rollouts, .550 settlement, 0.029-0.038 standard deviation) makes the player with 11 a 56% favorite cubeless, but a 46% underdog if his opponent has the cube. In this rollout, JF still thinks the player with 11 has an 0.072 equity edge, but I think the rollout gives way too little credit to opponent's redoubling and gammon chances. I undaringly predict that 6/5(2) 8/7(2) "crushes" all alternatives in rollouts, and that 6/5(2) 24/22 does better than 6/5(3) 24/23. (In a real game, don't be afraid to split to the 22 point with 11 if 6/5(2) 8/7(2) would leave a _direct_ shot at the blot on the 8 point. And, in a real game, be very wary of moving your last spare checker from the 6 point to the 5 point. More often than not, that one little move will come back to haunt you before the game is through.) ```

### Propositions

Choose roll vs. double roll  (Larry Deckel, Jan 1997)
Choose roll vs. double-roll  (Rafy Marootians+, Mar 1994)
Eight checkers vs. fifteen  (Raccoon, Feb 2006)
Fifteen on the bar  (Pete+, Nov 2002)
Monte Carlo 1998  (Daniel Murphy, Feb 2006)
No ones  (Murat Kalinyaprak, Oct 2002)
Opening 11 vs. Owning the cube  (Bob Ebbeler+, Aug 1999)
Tino Road Position  (Arthur+, Apr 2005)
Up in the air  (Daniel Murphy, Feb 2006)