I did this drill 3 hrs straight yesterday. It has 15 variations, I got through the first 5. I think I went up 5 fargorate points in 3 hrs. Note, Neil's has the balls frozen, but that didn't make sense to me, so I put them about 1/8" off the rails. I haven't felt this good about a practice session in years. Its originally from Bert Kinnister.
Neils' video:
My picture:
Neils' video:
My picture: