Is this a concept (the forearm being vertical or close to vertical upon shoulder rotation) that people tend to agree with? Or is it more like the whole inverted W debate?

not sure

BUMP!!! Is a forceful external rotation unnecessarily harmful?

Good question. How do we know if the external rotation is forceful, though? How do we know if external rotation itself isn’t already harmful to any specific pitcher?

If someone is “rushing” but his control is fine is it a problem? If someone doesn’t “rush” but is missing high is there a problem? Can a pitcher get their arm up too early?