Love Bill's lessons, always something to learn or remember.
He takes so much of the MYSTERY out of stick control and steers you in the right direction (unlike 95% of the YouTube "teachers" out there in YT land).
Thanks for the kind words guys. That video focuses on the even slightly different technique in many people's "matched" grip. The left hand tends to be more German grip, or at least is playing with German grip attributes (such that the thumb is unavailable to help with downward pressure and facilitate finger control a la French grip attribute). Most people's left hands should be way worse than their right and will stay that way (despite lots of hard work) until the modify the grip a bit to American where both the thumb and palm are available on top of the stick.
This is nice. I've had recent success by just doing pages 6+7 of Chaffee's Technique Patterns with my left hand for 30 minutes/day. These are just isolated single finger exercises of 8th notes, triplets and 16th notes.
I then supplement that work by playing the standard swing pattern with RH/RF/LF and playing all the triplets with my left hand and then playing the normal shuffled triplets with the left hand.
This has done amazing quick work with my left hand over the last couple of months.
What's highlighted in this video, a tendency for players to play very German with their weak hand was very true for me.