The five main types of grips used for backhands in tennis are the Continental, Eastern, Full Eastern, Western, and two-handed. Within the two-handed category are several combinations of left and right hand positions.
In the feature on forehand grips, we were able to greatly simplify the task of finding and remembering the grips by using just the base knuckle of the index finger as our one point of reference on the hand. With backhand grips, the base knuckle will still be our primary point of reference, but because more pressure is exerted on the thumb in backhand strokes, we'll have to keep track of it, too.
We only need to define three planes on your racquet handle for the backhand grips. The plane parallel to that of your racquet face is called the side plane. The top plane, which faces up when your racquet is on edge, is perpendicular to the side plane. The plane between the top plane and the right side plane is the upper right slant.
To find a Continental backhand grip, place your base knuckle on the upper right slant and wrap your thumb almost straight around the handle. This grip is poorly suited to hitting topspin, but it can be used effectively for slice and adequately for flat shots. It handles low balls well, finding most of its few proponents among grass court specialists, especially grass-court serve-and-volley players who hit fewer groundstrokes and like to use essentially the same grip for all of their shots.
To find the Eastern backhand grip (note the distinction from the Full Eastern), place your base knuckle on the right edge of the top plane and extend your thumb diagonally across the left side plane. This is a versatile grip, suitable for topspin, slice, and flat shots.
To find the Full Eastern backhand grip, place your base knuckle on the center of the top plane and extend your thumb more straight across than diagonally across the left side plane. This grip is favored by players who like to hit heavy topspin on their backhands, but it works well for flat and slice shots, too. As their names imply, the Eastern and Full Eastern are not greatly different.
The Western backhand grip is often defined as synonymous with the Full Eastern, but a more extreme Western grip places the base knuckle on the left ridge of the top plane. The extreme Western backhand grip is not widely used. It can generate heavy topspin, but it is poorly suited for slice or even flat shots.
For the two-handed grips, the left hand (of a righty) is most commonly placed in an Eastern forehand position, although the advent of more Western styles has many players turning it closer to the Semi-Western. (See the feature on forehand grips.) The right hand, resting lower on the handle, is most commonly placed in a Continental backhand position, but it can also take up an Eastern forehand or an Eastern backhand position. Two-handed backhands offer more racquet stability and easier topspin production, but they are difficult to use on low balls and for generating slice. Most good two-handers learn to use one hand for low balls, emergency stretch shots, and slices, and keeping the right hand in a Continental or Eastern Backhand position makes this easier.
If you have questions, please post them at our tennis forum.