One common piece of advice about serving in tennis says that you should use the same toss regardless of which spin you intend to hit, primarily to disguise your intention. The player most often cited as a model of always using the same toss is one of the greatest servers of all time, Pete Sampras. On the following pages, we'll examine the disguise an unvaried toss provides, how Pete Sampras tosses, the practicality of using the same toss for different spins, and several examples of what top current players do.
It's certainly true that a toss can provide an early signal of which spin the server intends to hit, especially if the toss is at either end of the left-right range. A toss well to the left will almost always lead to a serve with significant kick, usually a twist; a slightly low toss well to the right will almost always be a heavy slice--unless the player has a very odd and inefficient way of hitting flat.
Tosses closer to the middle of the range also give clues, mostly of what the upcoming serve cannot be. A toss even slightly to the right cannot be hit as a twist serve, although it can be hit with a significant amount of topspin that will give it some kick. A toss even slightly to the left cannot be hit as a heavy slice, although it can be hit with some slice if the player leans to the left enough before swinging.
Immediately following the toss comes an excellent clue about which spin the player is hitting: the swing. The swings for the different spins are quite distinct. For most receivers playing at the level where serves are hit with significantly different spins, reading the server's spin from her swing should not be difficult, and that information would be registered before the ball is struck. How much advantage does the server gain, therefore, by trying to disguise the spin by not varying the toss? Against receivers who can't read the swing well, the toss might be a better or an additional clue, but such receivers are probably rare. In terms of time, it's basically the difference between signaling the receiver one second before the ball is struck and signaling a fraction of second before the ball is struck, both of which are followed by the ball flying the length of the court before the receiver has to hit it. Whether the receiver reads the spin from the toss or from the swing, she knows which spin is coming by the time the ball is on its way.
