In every ATP season there seems to be a couple of players that come out of nowhere and surprise all tennis fans with how well they play.
For example, in 2006, Novak Djokovic came from around No. 70 in the rankings, and eventually by the end of the season, rose to 16th in the world. He has since become one of the most popular players on the ATP Tour.
Some of the players on this list you may not know but I think you will know by the end of the 2010 ATP season. This list consists of players that are no higher than 77 in the rankings but could be much higher later in the year.