The notion that we should hit “through” the ball has been around for decades, but what does it really mean? Can we really hit through the ball? How long is contact? With lighter racquets and faster racquet head speeds, is this instruction still relevant? If you’re curious to see if this instruction should be sent to your recycle bin, read on.
So just how long is the ball in contact with the strings? Through the use of high speed video, we know that the ball and racquet are usually in contact for 2-3 milliseconds, or about 1/250th of a second. Considering that the human eye cannot even see this fast an event take place, that’s not much time. (Note: The human eye can only see as fast as 1/60th of a second.)
And this is true for beginners as well as pros. There isn’t really that much difference between the different levels with regards to swing speed since some beginners swing quite fast also. The ball may not go in the court or it may carom off the back fence, but the swing may be very quick! Think of it this way. On average a 50 mph racquet head swing speed will create a 65 mph ball speed. Likewise, at higher levels a 100 mph swing speed on the serve will create a ball speed of approximately 130 mph.
So let’s take a 50 mph swing speed on a groundstroke as an example. Over what distance is the ball in contact with the strings?
It’s interesting to mention the swing speed on a groundstroke in relation to hitting through the ball. We never hear anyone speak about hitting through the ball on the serve, do we? The reason is that timing is much easier on the serve since the ball is more or less stationary in the air when we hit it.
To answer to the question, a 50 mph swing speed results in a racquet head that is traveling at 73 feet per second. This is incredibly fast when you think about it. Do the math — with ball in contact with the strings for 2-3 milliseconds you end up with ball and racquet contact spanning just 1.75 to 2.63 inches. Of course, it’s a little more complex than that since incoming ball speed and other factors will also affect the equation.
It’s really quite short. So, why would it be important for the racquet to travel forwards after contact, if the ball is already off the strings?
The reason is timing. Think of it this way. The faster the swing, the more challenging it is to precisely time contact. If the ball is contacted an inch behind or an inch in front of the desired point of contact relative to your body, you risk losing control over ball direction and trajectory if the racquet is not traveling forwards just before and just after contact. This is why coaches correctly speak about hitting “through” the ball.
Hitting Through the Ball
So, what does hitting “through” the ball actually mean?
Hitting through the ball has long been an instruction to encourage players to keep the swing path on a relatively straight path as long as possible before contact and also after contact. To understand it visually, picture a racquet with no strings that has a type of invisible force field that passes through the ball.
Tennis is an open sport. This means that incoming ball speed varies from shot to shot (what to speak of placement, height, spin, etc.). This is where the instruction of hitting “through” the ball or lengthening “through” your shots comes into play.
It is very easy to contact the ball slightly early or slightly late. We do it all the time. So, if players keep their swing more linear by thinking of lengthening “through” their shots, it will be easier to control the ball. Think of it like an insurance policy. If you swing a little late or a little early, hitting through your shots will help you hit more of your shots into the court.
Posted by Steven White Author and illustrator of “Bring Your Racquet” http://www.amazon.com/dp/1933794240