Jeff, it suddenly dawned on me, we may be talking of two different things here. Do you mean slowing down ball speed? Or approach speed? While the two are related I think there may well be differing ways of attacking each. Seems to me that the only ways I manipulate ball speed is the position of the ball in my set-up coupled with arm extension in set-up. I'll go from down below my hips (very slow, for me) to about shoulder level (last game of an 8 or 10 game block at Silver Lanes in Spokane [or most other places]. I also move the ball further from my torso when I want to generate more speed. My fastest ball starts at about shoulder level with my arms nearly fully extended; no pushaway, just drop.
To slow approach speed I crowd the foul line. This will, to some extent, slow the ball, but I do it mainly to slow my trip to the line for timing purposes.
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