How much is the probability of this happening?

I just got back from playing ping pong, and I saw something amazing that I simply must tell someone about. Ping pong players will be able to visualise this in their minds. The girl who was playing served and the ball hit the edge of the table. So it bounces right up high into the air. Now there are two ways it can bounce. It can either bounce forward (towards the other side of the table) or backwards (towards the server). Well, this ball went forward. And who would've guessed it, it hit the edge at the other end of the table! So it ended up as a good service, and there was absolutely no way the opponent could return it, since everyone thought it was out (even the server). So...let's just say...if you can master this service, you're on the road to greatness! :-P