An analysis of pro matches had a direct correlation of second serve defense and second serve return offense: the better a player did defending his own serve and breaking his opponents second serve= the higher they were ranked.
70% of pro lessons are given to people who hire a pro to teach them to serve.
All the top serve volleyers of years past used heavy frames and gut: sampras at 389g, edberg at 400g, Becker at 405g, mac at god knows what.
They needed the mass for serving, not for returning or volleying.
Now the norm is 365g. Delpo, djoker, fed, berdych, tsonga, almagro, etc. near that range.
Is there anything here that teaches us how to create vicious whip lash? How to increase our frame speed?
Can't be done without the coil and the snap speed of our forearm. Leg drive adds 10%.
The timing needed to get the frame moving over 100mph is difficult to learn. That's why so few can hit 130mph.
But if you do learn to, it sets you apart if coupled with accuracy. Not many club players ever hit one that fast, let alone average 120mph.
raonic oh serve
fed oh serve
harrison oh serve
becker oh serve