Well, if the fielder is still in the process of gaining control over his body after contacting the ball (and why else would he be running with the ball?), then the play is still going on, I'm sorry to have to correct you, but a voluntary release
is required. A voluntary release is one of the things we
do use, not
can use to determine a catch.
You're absurd analogy of F9 tripping over the pitcher's mound is the stupidest thing I've heard all week. I was speaking of the continuous nature of the play (as in immediately following contact with the ball), not a fielder running in 200 feet after the inning is over and the teams are changing sides. That would be ridiculous. Oh, and BTW, F9 is the RF, not the CF.
You tell me what is the difference between running 20 ft. with the ball, and hitting a wall and dropping the ball, and running 20 ft., falling down and dropping the ball. Both are during continuous action of the play, and both require (that's right
require) a voluntary release, as well as a judgment that the fielder had the ball long enough. One without the other is not how the rule works.
Here is the exact wording of the rule:
In establishing the validity of the catch, the fielder shall hold the ball long enough to prove that he has complete control of the ball and that his release of the ball is voluntary and intentional.