The serve is the most dificult part of any tennis players game to master.
Like the modern day tennis forehand, modern day tennis serve has also evolved.
Today's modern serve involves using leg and torsional rotational power
We need to fully understand the KINETIC CHAIN if we want to achieve MAXIMUM power.
Up to today, there are still a lot of tennis coaches who emphasises the SNAPPING of the wrist at contact as a key component in power in serve.
That is essential but IMO the snapping or I would put it as PRONATION is the end- RESULT of the full kinetic chain.
To say that most of the power coming from the snapping is a totally wrong concept
These are the few elements I would add as KEY to delivering a correct KINETIC chain for SERVE
Hope this helps.