Hitting down the middle of the court can be a wise strategy in key situations in singles play.  Many times people who hit approach shots try and rip the ball into the corners.  This can be effective against many players, but what about the player's who run fast and love to pass on the run?

Hitting down the middle of the court does not allow your opponent to hit with any great angles.  Therefore you should have less court to cover to hit your volley.  Try hitting the ball down the middle of the court to try and jamb your opponent and make them create the angle.  Making your opponent have to hit up and have to pass you will put extra pressure on them especially when there is no huge angle to shoot for.  If your volleys are stronger than your approach shot you may rather go for the winner off of a volley rather than the approach shot, especially if you were not in a great position to hit the approach shot and were forced to the net.

The closer you hit your approach shot to the sidelines of the court the easier it will be for your opponent to hit a big angle or to just guide the ball down the line.  Simply hitting the ball down the middle of the court cuts off the options for angled returns from your opponent and will force your opponent to come up with a great shot to get it past you.  

Good Luck on the Court!
Scott Baker
Tennis4you.com