You would think that with the philosophy of the A’s building through the draft someone would catch this, maybe they plan on changing his mechanics?

Does the fact that Ross is tall and lanky have anything to do with his inverted W? Just going by the freeze frames you posted, Prior seems to be driving his throwing elbow towards first base a lot more than Ross does – isn’t that where the possible injury comes from with the inverted W?

Does the fact that Ross is pretty tall and lanky contribute to his inverted W at all?

It almost seems, just going by the freeze frames you posted, that Prior’s elbow and upper arm are pulled back towards first base significantly more than Ross’ – I wonder if that may help him avoid injury. Well, that and teaching the kid to take a longer friggin stride, he’s probably giving up 2 or 3 mph on his fastball just by short stepping like that.

Yeah the glove side is outrageously high but the throwing arm side isn’t horrifyingly bad, just bad. But put that with the finish or lack thereof though and: yikes.

Is this arm action any worse than Gerrit Cole, the Yanks first round pick?

would it be that difficult to tweak the delivery?
he’s a tall, athletic pitcher, former SS..A’s and many other teams believe in good mechanics. he already throws mid 90’s w/ that delivery, if its cleaned up he might throw even harder.

I’m surprised that more teams don’t pay attention to this. As someone who pitched in high school and college (I’m now 31), I can attest to your points about the inverted W. I used to have two deliveries (for reasons I won’t get into). In one of them, I had an inverted W arm action and I ALWAYS had elbow problems. In the other delivery I didn’t use the inverted W and never had problems. Also, just a moment ago I tried just standing here putting my arms in an inverted W and you can just FEEL the impingement! My shoulder actually hurts a little bit from just standing like that! Somebody should really do a statistical analysis of how many major league hurlers use the inverted W and L and compare how many of them get hurt compared to those who don’t. I expect you’d find a huge statistical difference!

Huge difference between Ross and Prior. Ross has an invert on GS. Prior on throwing arm. Ross’ action on throwing arm is actually fairly common. What is unusual is to have a guy throw this fast, with such good results at the levels he has, with such poor mechanics. The A’s probably looking at his saying — it would be easy to add 10mph with better mechanics. The key question is whether they are actually willing to “develop” such a high draft pick. The tendency is to largely let them be unless they start tracking well below projection.