Posted a question for my buddy.  He plays up the boards with about med. Speed.  Like walter ray williams jr.  He plays around 7 to 12 board.  Sometimes he pitches the ball to the right out to 3 board.  Any idea why?  I watch his armswing and it looks good.

Got that right.  I can fix my own game just not someone elses.  Lol

I have heard the "Pros" say, if you do not cross your right ( for a righty) foot in front of your left , on the first right  step, you will throw the ball to the right in order to get it past your leg.
I have also seen almost every Pro extend his balance arm out to the side with his thumb turned DOWN!

An arm swing is created and predicated by many variables...body type & tilt and alignment as well as preferred timing...timing is termed as such that the body interacts with the arm and swing...where the ball is when it enters the actual downswing and how it depends on its positioning with the shoulders and hips...
A majority of bowlers that I have worked with over the vast years are at least a good full step out of time (look at Scott Norton) which does not allow the swing to properly interact with the proper movements of the body or the hip do not clear correctly to allow the swing to clear freely...thus generally creating a miss to the right or a over the top pull to the left, due to the fact the body gets in the way of allowing a free swing...or creating a rounder swing plane in regards to the body, both creating improper feeding of the ball into the downswing and into the lane
The things I would look at is proper amount of upper body tilt or the swing shoulder lower than the opposing shoulder and the ball in the proper alignment and placement going into the swing or the ball starting its movement back as the opposing foot taking its step
Shoulder alignment generally dictate direction ball travels off the bowlers hand...if the shoulders are being forced open to allow the ball to swing through, timing is not allowing the shoulders to return to the desired alignment thus a missed shot path

Feet are NEVER fast...they are stabilizers and are there to provide support for the upper body and the bowling ball...the reason why they appear quicker is they are needing to keep up with an upper body movement or the force of the bowling ball in a position away from a proper position or pulling the upper body away from a centralized position...similar to falling off balance at the foul line...it's deals with proper or improper timing movements

Foot speed indeed, is a direct function of upper body movement. Especially bowlers who
deploy a gravity-fed swing, the speed and tempo of the feet should synchronize with the speed and tempo of the armswing and not the other way around.