[Daryl]

The effective swing radius by the time of the release also makes a different. That should correlate prety well with hand speed.

Increased swing radius increases the effective moment of inertia - which is one of the "effective mass" parts. The other being active power during ball contact. Both of those will be felt as a varying degree of shock and impact resistance in the hands.

Lag Pressure and Lag Interval (Pivot Lag).