Blues are going to categorize your mechanics as "windup". As you read the rule book, you will see that they must. So as soon as the free foot swings in back of the rubber, the runner is gone. And the pitcher is committed to deliver to the plate. And runners will be loving it. Why do you think that pitchers use the stretch instead of the windup with runners on?
In reality, they will start going as soon as the foot moves back at all. And if the free foot is going back, and then it starts toward first the pitcher may well get a balk call.
Flail is taking the arm back farther than a line drawn from HP to 2B. Over rotation after break.
I am talking about feeling stress - tension if you will - in the shoulder and triceps. Not pain or discomfort. And if you don't feel it, then you would be the first person I've had try the demonstration that did not. And that is possible, but not likely. And no, I have not had shoulder problems.
I'm sorry, but you cannot say that my observation on the overhead slot is a misconception. I have seen way, way too much empirical evidence. And a knowledge of biomechanics provides the theoretical explanation.
First. Sandy's shoulders were tilted significantly. This lessened the angle between the torso & arm. Second, just because a pitcher who did use the overhead slot didn't go down with a shoulder injury does not mean it was less stressful.
It sounds as though you want to teach an overhand slot, but with inversion in an attempt to simulate overhead.
You might want to read Adair's book on the physics of baseball to fully understand the outfielder's judging of the ball. This concept is being somewhat misapplied here.
I can tell you that from years of watching baseball, pitchers who throw straight tend to get whiplash when they go up against good hitters. And I don't think you are considering reaction times and late movement (e.g., as with a good two seam). Late movement is tough because while the eyes might recognize the movement, the body has already committed to a swing based on an earlier perception of the ball's path. And it cannot react quickly enough with adequate control to adjust.
And if you want to use a pro to justify an arm slot, you may have noticed that Clemens uses the three quarter.
We as coaches must remember that often the pros succeed in spite of things in their mechanics. Not because of them. They have so much incredible talent to have made it that far, that they can overcome these things.
Do you teach the Marichal leg kick? Why not? He was a great pitcher. Do you teach the Tekulve (sp?) submarine slot? Why not? He was very successful.
Again, are we talking about what to teach youth pitchers? Analyze the mechanics in the light of physics and biomechanics. And keep it fundamental.
And pulling the elbow back as the throwing arm goes forward increases rotational speed. It is providing a force acting to rotate the torso. Leaving the glove tucked does not provide this force. And I never said the glove arm had to be fully extended in front of the body nor that it would fly out. I don't teach that. The upper arm should be parallel to the ground, and the forearm hanging down at 90 degrees. Then the elbow is pulled back. So now, the laws of physics do not say the opposite of what I am describing. You are ignoring the rotational force applied by pulling the elbow back.
I think we have just about beat this one to death.
I do hope that if you are coaching youth pitchers, you will reconsider what you are describing here.