No Kidding, Really?

I guesstimate that 90 to 95 % of all recreational level/ 2.5 to 4.0 level tennis players have a few misconceptions about what they should be doing as they execute their strokes.

The most glaring and insidious is the concept that top players actually flip or roll the face of the racket over the top of the ball when they hit a topspin shot. 

The reality is that the hitting surface is almost perfectly vertical on most topspin drives and slightly tilted forward (just a few degrees) if the hitter is playing the ball as it is still rising upward from the bounce (that slight tilt keeps the ball from deflecting upward as it leaves the strings).

The spin is imparted by the upward brushing action of the racket face on the back of the ball as the swing drives it toward the intended target area. Top players can increase or decrease the amount of spin they produce by brushing the ball more or less dynamically through the contact zone.

The other most commonly misunderstood technical issue is the weight shift during the service motion.

I'd wager that 25% of all the private lessons I've given over the last 50+ years is to solve a problem with the ball toss.

The issue more often than not is the player transferring their weight onto their back foot as the ball floats off their fingertips (that action pulls the ball back toward the server, rather than placing it slightly toward the net).

When I point it out, I generally get the argument that all of the players they've seen on TV or watched in person at the US Open or the  Miami Open Tournament rock back as they toss, then launch themselves using their back leg as the driving force.

Nothing could be farther from the truth! 

A fairly high percentage of top players deliberately lock their weight firmly and dramatically on their back foot after they've toed the line and bounced the ball a couple of times. Others do have a front-to-back foot shift but then begin shifting toward the front foot as the lifting of the ball begins, and then using the front leg to explode upward into the ball.

Generally, once they buy into the concept and practice it a few dozen times the toss becomes more controllable and consistent and the serve more reliable and accurate.

Tennis is very much a Technique Intensive Sportand inasmuch,without sound technique, players will hit a stone wall in their path to higher levels of play. 

Get good information from your coach - ask them questions until you understand and can buy into the concept. Then, and only then, invest time to develop, hone and polish the skill you are hoping to improve.