March 17, 2018 Chouette Results

We had a great turnout for the chouette today – 12 players over the afternoon, although no more than 10 at any one time. Newcomers Oggie, Oliver, and Nate had not done a chouette before, and so we set up a beginner’s table for $1/point, and the main table went for their usual $5-10/point.

It occurred to me that a sport’s bar is really a perfect spot for the chouette, because they had about 7 different events on various screens, and it was totally not out of place for a table to suddenly erupt in a cry of joy and/or despair. We had a lot of those for the backgammon games too, and more than once I found myself saying “all I need is a double <insert number here> or better…”, either to win or to save the gammon. I think I got my roll each time, too!

This position came up in one game where Oliver was the captain, and we spent a solid 2 minutes debating.

gnubg-danbu_21p_2018-03-17

The debate was: 7/3(2) or 24/20(2). Turns out, we went with the wrong answer. Extreme gammon says it’s 7/3(2), and by going with 24/20(2), we made a -0.004 error. Which is to say, you couldn’t really go wrong with either of those plays.  +0.934 equity or +0.930 equity – I guess one is slightly higher.

I have a couple of other positions from my table where there was a doubling decision, but running them through Extreme gammon shows the answer we arrived at was not only right, but kind of obvious.

Mark F sent me a couple of positions from the other table that were interesting. Brown was the box in our chouette yesterday, with white on roll. There were four 4-cubes on White’s side of the board. What is the cube action here? Note that brown has 8 checkers left on the one-point.

Untitled1

In the actual chouette, all four team members doubled to 8. The box took all 4 eight cubes. The box lost, and questioned his take. But it was a very easy take, and in fact, it would be a huge blunder to drop. In fact, it was not a proper double, and white’s error was .045 by doubling (a fairly small error).

Note that white will be very disappointed they doubled after white rolls a non-double and brown rolls any double. Also, if white rolls a 1 or a 2 (other than double-2), black still has a take next roll.

 

Later in the afternoon, another bearoff cube action came up:
Untitled12

After learning about the previous position through XG mobile shortly after that game, brown was reluctant to redouble. And he didn’t double. But actually, it is a clear double. And a double-blunder not to double! Here, brown can be off in 3 shakes without rolling a double, whereas white needs four rolls unless he rolls a double. That’s a huge factor. White barely has a take. The cube equity after white taking is .961, so it would only be a small error for White to pass.

Lots of excitement was expressed about next weekend’s Portlandia Backgammon Classic, and I’m super pumped for it. Hope to see you there!

-Mark