With all the surprise upsets at this year's Wimbledon tournament, how did the top players fare in the most recent rankings? You'll find the answers in the latest women's singles rankings.

People unfamiliar with the ranking system used in professional tennis, both men's and women's, will probably be scratching their heads. Venus Williams was #7 in the world before her amazing run to Wimbledon championship, and after it she stands at ... #7. Serena Williams, who lost to her older sister in the championship match, did move up one spot in the latest rankings, from #6 to #5. (You can find the full rankings on the Web site of the WTA Tour: http://www.sonyericssonwtatour.com/2/rankings/singles_numeric.asp )

Tennis uses a ranking system that measures not a player's performance during a calendar year, but on a 52-week average. Also considered in a player's computer ranking are the number of tournaments played, the relative importance of those tournaments, etc.

Venus and Serena Williams have each played in 13 tournaments in the last 52 weeks, according to the rankings. Top-ranked player Ana Ivanovic has played in 17, while #2 Jelena Jancovic has played in 22 tournaments. Maria Sharapova has played in 14 tournaments in the last 52 weeks, but the other top 20 players competed in anywhere from 17 to 29 tournaments.

Fans of men's tennis probably aren't any happier with that sport's computer ranking system: Despite defeating world number-one player Roger Federer in two grand slam finals this year, Rafael Nadal still is the number-two player in the world, right behind Federer, who is having an off year by his lofty standards.