If your racquet is down too low when the ball is bouncing high, and you are making contact up above your head, the result is that you have poor extension through the ball, your power declines, you must hit with a high trajectory and/or lots of spin. It is possible that you may hit the ball on the frame of the racquet. Note that this is not necessarily bad if you are intending to return the ball with a high looping trajectory.
If you have the wrong grip (not western enough), you can expect the ball to fly long with no spin, or even over the fence if your opponent is hitting the ball at you with topspin.
If your legs are stiff, you can expect poor power, constantly reaching for the ball, shoulders too open (no splitstep), and that you continually lose points when the ball is hit short in the court or low height.
If your stance is closed off, you will likely hit the ball late, and it will go out wide of down the line. Your hips cannot come through the shot.
If you are consistently hitting the ball too late (going wide down the line), it may be that your swing is too big, you are too slow to turn, or your footwork is too slow.
If your shoulders are too open, you will likely see the racquet going way behind you, the ball flying all over the court / loss of control, and either wide down the line or wide crosscourt.
If you fail to drop the racquet below the ball before swinging, you can expect to hit a lot of balls into the net. This is usually caused by / goes together with poor knee bend.
If you are taking the racquet back instead of doing a unit turn / shoulder turn, your arm may be too straight, resulting in the racquet going behind you, erratic results, poor control, and a slow motion. You will have poor body rotation and poor racquet head speed.
If your leading toe is not pointed in the right direction (towards your opponent), you will be off-balance after the shot, and your body momentum will continue in the direction of your toe – off the court potentially. Your shots will be more defensive in nature and not penetrating.
A lot of juniors get their elbow in too tight to their body, which facilitates a wild take-back of the racquet, and difficulty controling the swing. Instead you want to keep the racquet well out in front of your body in the ready position, and maintain that distance between your elbows and hips throughout the swing.
Try and pick out what things I’m doing wrong in the below two videos! It’s fun being a critic!
And hopefully now you know enough to scoff at other people’s poor technique next time you’re out on the courts.