I opened with 6-1 and made my bar pt.
Opp. rolled 5,2 and played 13/11 13/8
I rolled 4,1 and played 24/23 13/9 (a 0.058 error) best play was 13/9 6/5 (slot).
I always seem to get this type of play wrong, if somebody could explain the reasoning I may be able to unlearn this bad habit.
Thanks

There are a couple of things happening here. First of all, you are immediately threatening to turn your position into a powerhouse 5-prime immediately. Secondly (and more subtly), in general when your opponent takes 2 men off the mid you should be inclined to play on your own side of the board and slot and things like that. They've invested time in bringing builders into play and they can't both use those builders and hit you. Also, by playing down in response to your making the bar, your opponent is playing catch-up and trying to fight you in an aspect of the position in which you have the advantage instead of trying to build up a different type of advantage, like an advanced anchor. As such, you are justified in pressing that advantage and making his catch-up play even worse.

RolledUp, this analysis makes a lot of sense and is a big help. Since posting I have run the move through XG rollout and my play is even worse (0.072 error) and is now third behind the bland 13/8.
Thanks for the help, it's appreciated.