explanation for terms used in PBR comments

Since you ask, I have the same question on this. I'm assuming it's bad, but not positive? Fields and throws flat-footed, funnels ball deep into body occasionally,

Flat slide the way I have had it described to me is that it breaks, primarily two planes.  If you break the hitting zone into 4 planes and go clockwise 1,2,3,4 it really only goes from place Zone 1 to Zone 2, it sweeps across the plane as opposed to go from 1 through 2, into 3.

Flat footed means heels are on the ground when fielding and throwing as opposed to the balls of your feet.

"so I'm pretty sure that's what a "recoil finish" means"...watch slow mo youtube video of David Price...he has a "recoil" in his delivery.  Basically the "brakes" are coming on before the pitcher finishes his delivery down and through.  The "spinning" toward first base is probably the result of the recoil in the finish or follow through. 

"Underneath" the pitch to me means the elbow is falling below the level of the shoulders in the delivery which will cause the pitch to "flatten out" and not be on a downward plane.  If the throwing elbow is in alignment or very close to it with the tilt of the shoulders  the pitches won't be flat unless the shoulders are flat...i.e a sidearm delivery.

Hard to tell the cause of the issues but I've seen both of these result from the front side pulling open during delivery.  If you don't already have one get a good pitching instructor.  The velo is good for a 2019, "loose, quick arm action" is good comment and if he gets the mechanics cleaned up hard to tell how good he can be.  Good luck.

Iowamom23 posted:

Since you ask, I have the same question on this. I'm assuming it's bad, but not positive? Fields and throws flat-footed, funnels ball deep into body occasionally,

Yes, those two items are actionable.  Quick, athletic, fluid movement through the fielding and throwing motion will involve weight distribution mostly on the balls of the feet.  There is heel touch at times but very little weight distributed there.  In this context, flat-footed usually refers to a bit too much heel strike or weight back.  Agility and ladder drills are great for this.  

Somewhat related, an infielder wants to play the ball, not let it play him.  Attack and work thru the ball whenever possible.  When funneling is necessary, use a short fluid funnel, keeping the hands out in front (as opposed to pulling the hands/glove back into the gut to field the ball).  When an IF lets the ball funnel too deep into the body with any degree of regularity, he is letting the ball play him and not trying to work thru the ball out front.  Son should share the assessment with whoever his primary fielding instructor is and it should (hopefully) help them know what to work on the most with reps.

While we are on this topic, saw a PG eval that referenced a pitcher "with short arm action".   What does that mean?  The only explanation I've heard was that the player wasn't getting full extension and was potentially limiting velocity? 

I think it usually relates to a smaller circle, shorter take back (Brian Fuentes), less forward arm extension/finish or a combination of.