|The world's sharpest tennis serves|
|Around the Academy:
The serve is a crucial part of a tennis player's game.
And nobody on this planet has got a serve as big as the one and only Andy Roddick, whose incredible 155mph effort will certainly take some beating!
Serves have to be powerful and accurate.
Today's tennis stars are hitting the ball faster than ever before.
Some of the biggest hitters on the men's circuit regularly top speeds of over 140mph.
But a blistering serve is not always down to a player's style and physique.
A lot of it is to do with the racquets they use.
Instead of the old wooden frames, tennis racquets are now made of lightweight materials such as graphite.
The racquet heads are also larger which means they have a larger sweet spot.
But speed isn't always a good thing.
Many spectators believe the sport is becoming boring to watch because there are less rallies.
Now a new ball has been developed which could slow the game down again.
The new ball is bigger which means it travels through the air slower.
And that could mean bad news for some of the sport's master blasters.