SA, two reasons why I think this distinction is important. one I believe imagining throwing more horizontal is more helpful in achieving max rhs thru the optimal contact swingpath. remember rafter saying 11 to 4 swingpath? it helps you to accelerate the racquet head more thru the swingpath toward the target.
two the first idea helps you maintain the contact point more out in front and it helps setting the limit how far you can windup and go down and up before reaching the contact point with the good swingpath in max speed.
emphasizing upward accelerating more than thru swingpath can tilt the contact point more backward compromising the quality of serve for excessive emphasis on topspin.
Last edited by boramiNYC; 09-22-2013 at 07:24 PM.