Where he found the idea is browsing some of Marshal’s stuff. His “max-line screwball” grip looks sort of like a hybrid of a circle and 3 finger change.
It’s been a while since we’ve spent time taking a look at what he teaches. As I recall though he advocates throwing over the top and lots of pronation. That’s where I came up with the idea that the screwball was an over the top specialty. That and my son spent some time talking to a former big leaguer that talked about throwing it to get right handed pull hitters to give him a ground ball. He threw conventionally.
Anywho, after one day of playing with this it could be spinning both ways that you (4pie) are describing. A work in progress in it’s infancy for sure and there was inconsistency. And to be expected especially watching him focusing on grip of the ball and how to release it - his overall mechanics weren’t near as graceful. It did seem surprisingly easy to him though when he threw a few nice ones, so I can buy it fitting his low 3/4 style.
What’s really encouraging is that last night he threw against a friend’s all star team in their practice helping them get ready for their district tournament. He likes to sink his 2sfb, but concentrated on trying to get it to bend back toward righties. Not something he’s had much consistency with, but feels like he found it last night. Now he’s really hot on being able to throw two pitches with similar movement, but at different speeds.
This has been a year of adapting and evolving. On the small field he just threw it by batters and his breaking stuff wasn’t as good, but was really effective because reaction time was less. This year he’s pitching to contact a lot. Likes to show the 4sfb mostly in, and locate down and away with a 2sfb, and then mix sliders in that mostly finish out of the zone. He’s not bad at hitting spots (been getting lots of ground outs), but misses a lot too. Really needs to put that tool of going softer to change speeds in his bag.