Martin Kaymer golfer in the world, making him only the second German (after Bernhard Langer) to be the top-ranked golfer in the world. At the time he was the second youngest to reach world number one behind Tiger Woods, soon surpassed by Rory McIlroy in March 2012, who gained the top ranking at age 22. In April, he relinquished his number one ranking after eight weeks to Westwood, who won the Indonesian Masters. After reaching the number one ranking, Kaymer decided to undergo a swing change to be able to move the ball both ways. Frustrated with his disappointing results at the
US Open Series purse. The amount depends on their US Open Series placement and US Open result. If both are won then the bonus is $1 million as of 2010. Lleyton Hewitt and Lindsay Davenport were the top point-getters in 2004, Andy Roddick and Kim Clijsters won in 2005, and Andy Roddick and Ana Ivanovic won in 2006. Defending US Open champions Roger Federer and Maria Sharapova won in 2007. In 2005, whereas Roddick was upset in the first round against Gilles Müller at the Open, Clijsters became the first player to win both the US Open Series and the US Open, receiving