In my experience the most common problem for the backhand ground stroke lies in poor setting up of the stroke prior to making the forward swing. Nearly always an incomplete setting up. This can be ….not doing enough footwork tracking (which leads you to the correct place on the court). Or not fully completing the turn of the body (in particular the shoulders) tied in very closely with not a large enough backswing. If this does take place……you will automatically have to compensate in your forward motions. The motions of forward racket swing and forward body swing. These two are heavily connected to when to swing forward and where is the point of contact.
Another key item is how long your racket stays in contact with the ball. Now I know that in real time this time slot is measured in milliseconds; however I also know that one can feel the difference in the length of time/ contact between a perfect stroke and a compensating stroke. Hence my Perfectlesson Book Series has the sub title Tennis with Feeling. In my private lessons I ask the pupil to visualize either Djokovic or Serena Williams stroking a backhand, and that the pupil sees the champion make contact for four seconds. Then I ask my pupil to hit a ball and I may say “you made contact for only 2 seconds”. Next hit I may reply “better, that was 2.5 seconds”. Next hit I may say “ that was terrible, only 0.5 seconds”. Next hit I may say “ much better, that one was 3 seconds”. And this way, if the pupil continues to work they get to hit more through the ball and gradually increase the length of time the strings stay on the ball. I will say it again, the actual time itself is small, but the feeling is completely noticeable and you can easily tell if you have stayed on the ball for four seconds or not.
You can do this by yourself. Get a coach or good player to feed several balls to you…..normal balls more or less to the same place…..and see if you can improve this area of your game . If you are still making contact for less than four seconds you will almost certainly have an error in your stroke.
Another very common problem is not enough upper body turn and not a long enough backswing.
The single handed backhand needs more of both items compared to the double handed backhand. Thus the right foot for a right handed player using a one handed backhand should go past the normal line of the feet. The back of the hitter will almost be facing the opponent. The double handed backhand does not need a backswing as long as the single handed backhand does. But this often leads to a player not making a large enough backswing !!
The sequence of events I find to be tricky. The pros definitely turn first, start running towards the future point of contact and take their racket back as they are running. They are never late with taking the racket back and swinging forward to the ball. However in faulty backhands I see many players with a late backswing. But how to best correct that ? For me I find that I need to get the pupil to concentrate on the backswing being early. Sometimes so early that this slows down their movement to the ball. But to me this is the only way the late backswing can be corrected.
I also find that most people with late backswings have not mastered the correct footwork. How many steps to take, where to put them, when to do them ? All adding up to an incomplete setting up.
So the correction formula I have found to work best is to have the pupil focus on the following items and follow this sequence of events. First turn fully and take the racket all the way back. Then run to the ball, concentrating on taking many steps and having time to get into the right place. Then stop (hopefully in the right place and before the ball gets there). Then wait for the ball (even if only for a split second). Then make your forward swing, on time and smooth and 100% through the ball. This may be a bit mechanical to begin with ? But if so it will only be because some things are a little too early. In time the player will fine tune all their movements; but never be late with their forward swing and therefor never late with their backswing.
This system is the same as the job a pilot has to do before take off. Double check that everything is working properly (stroke preparation) before contact. Only then start the take off (swing forward at the ball).
All I can say is this. You can never do any harm to your stroke by doing special work on increasing the amount of body turn, the length of your backswing and extra footwork. The biggest requisites in this are having the time to do things (earliness) and following the correct sequence of events (when you are trying to break old habits).
If you are having trouble with your backhand you should first try the above items.
When you swing forward make sure it is a smooth swing, not rushed and jerky. If you are actually doing many items too much, that is much better than doing too little. You will easily fine turn it at a later stage and eventually look like the pros. Serena Williams is very early with her backswing. You cannot go wrong by copying her ! Good luck.