Usain Bolt will put his famous “Who faster?” taunt to the test again at the world championships. So far, it has worked every time it has mattered most. Ever since his stunning world records and gold medals in the 100 and 200 meters at the 2008 Beijing Olympics and his repeat at the 2009 Berlin World Championships, the Jamaican sprinter has turned into one of the true global superstars in sports. So when the championships open Saturday, most of the attention will focus on Bolt. Not that he minds. As usual, he is already making light of the pressure and expectations. “I am always confident. I am unbeaten this year and aim to defend all my titles in Daegu,” Bolt told The Associated Press in an e-mail exchange. On top of his individual gold medals, he also helped Jamaica win titles in the sprint relays at Beijing and Berlin. Anything less than a haul of nine gold medals from Beijing and two world championships would be a disappointment for him ahead of the 2012 London Olympics. Yet he is in some need of another overpowering show at the 53,000-capacity Daegu Stadium, because his statistics over the past two years have not completely matched his braggadocio. When it comes to “who faster?” in the 100 in 2011, Bolt is not on top of the list. He is not even the top Jamaican. His compatriot Asafa Powell holds the leading time of 9.78 seconds, with Bolt posting the sixth-fastest time of 9.86 – way off his world record of 9.58. He is not worried, though, having been in similar positions before. Two years ago, Tyson Gay was fastest ahead of the world championships but when it came to the biggest matchup of the competition, Bolt blew everyone away with a world record. “I think it will be the same as Berlin. Some people ran well in the early season but it is the championships that count,” Bolt said. “We always train to peak at the major championships. My coach sets out the program with this as the goal.” Gay had been hampered by a sore groin in Berlin, and injury caught up with him even before the championships this year. The American pulled out of the 100 meters at the US nationals in June because of a hip injury. Bolt was troubled by a bad back last year, and even if his times have been less than exceptional since, he says it no longer bothers him. “The back injury was last year. I haven't had any problems with it this year,” he said. Just don't count on world records this year. It leaves Powell as his main challenger to Bolt, but the former world-record holder has been notoriously pressure prone when it comes to big events. Bolt concedes, however, there is no underestimating Powell this year. “Asafa has always been a good athlete. He has been running fast for many years and deserves a lot of respect for his achievements,” he said.