If you are a 4.5 or even a 5.0 player, will you have a proper motion compare to Roger or Stan?
Another point - what is "a proper motion" for open stance and (or) open grip serve. We all know the beginner version that is not proper, but do we know the advanced "proper motion"? Since no high level players have ever used a true open tennis serves (option A, B and D), the proper motion is still waiting to be developed at top level (VW and Stan both opened somewhat, but still a little short to be qualified as open tennis serves, similar to the counter part in open ground strokes).
In short, you don't even know what is the proper motion in open tennis serve context. I know a lot more, since I've been practicing for almost three years now.
What level is this serve???? Like I told you a couple of times already: your OVERALL level of play DOESN'T MATTER regarding wether your serve is good or not. Heck, this guy won a SET at a PROFESIONAL ATP TOURNAMENT serving underhand (the ONLY relevant thing to notice here is that the opponent, Polansky, was caught off guard completely, nerves got to him and he just ran out of ideas when he started missing several "easy" returns and got tighter and tighter...., NOT that this way of serving is any good nor that it should be taught, or worse, described as an "effective 7.0 level serve").
So you might (or might not) be a 4.0 RATED player (you get the rating due to results, IN SPITE OF YOUR SERVE), it doesnt mean that your serve is a 4.0 level serve (again, youre rated 4.0 EVEN THOUGH you have a terrible serve).
The whacky, somewhat amusing fact is that, with a better serve, you surely would have a HIGHER rating than you do, your serve is a handicapp that can be easily exploited. I'd much rather have PLACEMENT than PACE. When I dont have to move (hitting a return on y forehand or backhand with just a half step), I have NO TROUBLE returning a flat 100 mph + serve, I can even be quite aggresive with them if there is no good placement to the courners or body.
We see pros making aces with 80+ mph serves out wide, taking pace off but sharping angles. You're trying to impress us with your flat what, 60mph serves with NO placement whatsoever?
You got it all wrong, you dont understand tennis it seems...