I watched a demo on turning the barrel a few years ago. They use a device called the bat broom. One side of broom is red the other is blue. Top hand was the key
If you hold it too tight the wrist will roll and you will see the red instead of the blue at contact.
I would like to see that demo and the broom, students like to have visuals and toys, specially if they work.
Here is a clip, from u tube, of Tewks "turning the barrel".
mann's Photos : Photo Keywords : turnbarrel*
i continue to look for the whole clip, because he demonstrates the pivot point also.
For the ones that understand, the 'hitters box" approach, it is one and the same.
both work well on arm positioning, and hand/wrist work, just add tilt.
While I understand what he was trying to illustrate - I would not use that clip as a model. That is why I posted the triangle video clip of Larsen.
MTS, when i picture and look at "turning the triangle", alls i get is the rear elbow in front of the hands. bat drag. chicken wings.
I am after good front arm work, and good rear arm work, which i like turning the barrel, and use the box, as cues.