A recent thoughtful article about baseball's best pitches (i.e. fastest speeds 100+ MPH) in the New York Times offers fascinating insights for the modern tennis serve.
The best way to produce the fastest baseball pitches -- and also maximize injury prevention -- is a bullwhip-like kinetic chain motion.
Maximum rotational speed shoulder. An upside-down tornado. The arm twisting and turning on the same plane as the shoulder in sequence, whipping the ball. The creation of maximum leverage.
Some obvious lessons for tennis serves.
(Photo Credit New York Times)
"When Radar Gun Hits 100MPH, There's More than Meets the Eye", New York Times, by Greg Bishop (June 20, 2009)