The basics of positioning at net are black and white with a lot of gray area mixed in, too. Let’s keep it simple and chat only about the basics of playing the net when your partner is serving. While you may stand anywhere on the court, the best position is up at the net. When you are at the net you have two main objectives: to win the point, with your volley, and not to lose the point.
To win the point you must be able to volley for a winner. To hit this type of volley, how close to the net should you stand? You want to stand close enough to the net to put any volley away. The farther away from the net you are, the more difficult it is to accomplish this. Standing very close to the net makes it easier to hit a winning volley. Standing too close limits your reach and makes you susceptible to the lob. Each player will have to decide how close to the net he or she can stand and still feel confident in putting the ball away.
The second object of not losing the point means protecting your alley. If your opponent hits into your alley, he or she will win the point (unless it’s a lob and then your partner will be able to retreive it). You must stand close enough to your alley to be able to volley any attempt to go down it by your opponents. At the same time, you want to cover as much court as possible, thereby giving yourself the greatest chance to hit a winning volley. A good rule of thumb is: Never stand inside your alley. At the same time, you must look for an opportunity to poach towards the middle for the volley. So stand next to your alley, not in it. Next, we want to follow the ball as much as possible as long as we stay in between the singles sideline and the center of the court. Crossing the center line will give your opponents a very good look at your alley, which we cannot let happen.
All players from beginners to the pros have these two objectives when their partner is serving. They will be standing in different positions but still have the same objectives. So keep moving and put that volley away.