Best move and why?

I played 18/13 18/12 which Gnu says is inferior to 13/8 13/7.

I still like my play...

Hmmm I'll take a shot at this one...Race is close to even after the roll. If the next roll sequence is hit/fan I think red can claim with the cube, and he'll fan about half the time so 3/36 of the time red claims an immediate point. If Black holds the defensive bar I think red will have to make a concession on a lot of his next rolls, either giving up an outfield point or hurting his board. If he moves inside, of course, he hurts his race chances.

Black will have three spares to work with on the bar and 8 points and his timing for this mutual holding game SHOULD be better than red's. With many rolls red will break the 11 and black should be able to move off the defensive bar more safely than at present with a lot of rolls. If red's first point to go is the 8, there's a good chance he'll have to leave a shot clearing the 11 or break anchor at an inopportune moment. I like GNU's play.

Incidentally, I'm really pleased with myself for this analysis and wish I could come up with this stuff over the board :-). I'm curious to see what everyone else has to add.

Black leads by 2 pips after the roll, 114-116. Playing 12, 13 leaves 6 shots, playing 7, 8 leaves zero shots. Since there's nothing wrong with 13/7 13/8, avoiding the 6 unnecessary shots will trump everything else.

To me this position correlates to my posting on Magriel's BG about week ago, the substantial difference between the two positions being whether the shot left is forced or volunteered.

My logic in this position was I clear the back men with a small amount of risk in order to have smooth sailing going forward. What I didn't fully appreciate was that my opponent was almost out of gas with his outfield men and may leave another shot soon. Between that and the shot being volunteered I now see why 13/8 13/7 is superior.

There was a time when I thought that backgammon strategy was more complex than what it actually is.

After doing a few experimental games against a pro and Snowie I changed my mind.

The basic priniciple is that a single game is always basically just a race regardless of the position. The idea of a primed board is simply to put you further ahead in the race.

Now, if this is applied to the position at hand.

By leaving a potential blot you are risking going furher behind in the race.

any 4-3, 5-2, 6-1 (1/6)
puts red ahead in the race when they hit you on 12 and you lose 13 points of advancement.
Any other roll red does not have to leave a loose one to hit

To come off the bar would need 4-1 4-2 4-3 4-4 4-5 4-6 1-1 1-2 1-3 1-5 1-6
20/36 and only one of these offers a risk free re-hit which is 1-1

When given the choice of not breaking your board the rule is never leave an unnecessary hit.

Here, your back point allows you the chance to hit red on as he advances and the pieces that red has back does not restrict any of your rolls when you have spares on the 7 and 8.

There are countless examples where leaving an unnecessary shot is the right play, usually situations where the play gains tremendously when not hit.

This position happens not to be one of them.

Agree here. And clearing the 13 without leaving a shot still won't a piece of cake when you don't get hit, so you're not getting that upside by leaving the shot now.