Sigh... can we please drop the arguments here? It all began with this:
Originally Posted by NTRPolice
She is not a 4.0 if her first serve is going 50 mph.
This claim is equivalent to: for everyone whose first serves are 50 miles/hour or less, his/her level is less than 4.0. This statement is so logically strong that it is easy to prove by contradiction. All we need to show is that there exists someone whose first serves are 50 miles/hour or less AND plays at 4.0 level or higher.
Consider the following thought experiment: Federer plays tennis under a restriction that his serves must be 50 miles/hour or below. Would he still play at 4.0 level or higher (e.g. destroy NTRPolice head-to-head)? Sure. QED.
In case NTRPolice doesn't understand logic, the key point in words is this: don't make claims about other people or players when you have insufficient information and knowledge. Always give others the benefit of the doubt. This may fare well in your social and work life in the future.