[12 piece bucket]

Lagster,
Perhaps the left leg at finish is an indicator of the direction and the type of force being applied. Example, Left leg straightening and backin' "up an in" ...is Centripetal Force maintaining/diverting forces around the axis to strike the ball maybe for a "cut shot". Then if the left leg is buckled forward and still bent slightly then perhaps the player is trying to hit a "high-draw" with a slide along the delivery line that moves the lower part of the axis well forward and working "under and up" aka: Danny Noonan of Caddyshack.
Food For Thought!!!
Linear Force -Angle of Aproach - Line Delivery Path - Hip slide"along" or parallel to Delivery Line -
Rotational Forces - Arc Approach - Turning hip around into the Release. See it ... I don't know ...just a hypothesis ...well I don't know how educated...but definitely...definitely...a GUESS!

Machine Addiction,
Annikan

Sounds like solid analysis to me. Good post! I haven't thought of the finish position in this way.