Here's some statistics from a Challenger Event in Prague currently being played on clay. Some fascinating scores and information regarding certain players with apparent form and reputations. There are no certainties in the sport of tennis, this tournament proves it;
Joao Souza is ranked 70 in singles and was the number one seed in Prague yet he went out in the first round to a guy named H Podlipnik-Castillo who happens to have a current ranking of 208.
Castillo then lost his next match to J Kovlavic who is ranked 190 by a score of 4 and 3.
Castillo then lost to a player who used to be ranked top 50 Alberto Montanes, a man who has won over five mil in prize money.
The Prague Challenger also saw another Djokovic take the court, Djordje, ranked outside of the World's top 1500 players. He lost easily first round.
That was all in one half of the draw. The other is full of guys ranked around the 150 to 250 mark, all trying to gain enough points to further their ranking. Difficult to make an impression though when you have players like Montanes battling to get their ranking up again after injury or poor form.
Tough sport tennis, not for the faint hearted but definitely for the players who have plenty of zero's already at the end of their bank statements.
Having a back up is a necessity, nothing is guaranteed........