g. A foul ball is a batted ball that goes directly from the bat to any part of the catcher's body or equipment and is caught by another fielder. (5-1-1d2)
I'll take a stab here...
This is the rule for foul 'tips'...if a foul tip goes into the catchers body and not caught immediately by the glove it's considered a normal foul ball.
This matters when:
> 3rd strike is caught - must be caught 'clean w/ glove' and not after contact with body or equipment by the catcher. (runners can advance at own risk unless 3rd out obviously)
> 1st or 2nd strike - runners can't advance on foul tips that aren't caught clean with the glove (but a direct foul tip into the glove caught & runners are at their own risk!)
Foul tips can rebound off the catcher's body, so long as the FIRST thing the ball touched was the catcher's hands or mitt.
If the ball hits anything other than the catcher's hands or mitt FIRST, then it becomes a plain old foul ball.
Example: Ball is batted sharp and direct (meaning, in a relative straight line, with no perceptible arc) back to the catcher. The first thing it hits is the catcher's mask, shin guard, chest protector, bare arm, foot, etc. This is a foul ball.
Ball batted sharp and direct back to the catcher. The first thing the ball hits is the catcher's mitt. Ball then skips off the mitt, goes into the catcher's helmet, bounces up in the air, comes down and is trapped against the catcher's chest, then is grabbed and securely held in the catcher's bare hand. This would be a foul tip- live ball and a strike to the batter.