World number two Roger Federer launches his bid for a sixth U.S. Open title, and his first since 2008, with a first-round match against Argentina’s Leonardo Mayer at the Arthur Ashe Stadium on Tuesday. The 34-year-old Swiss has been in sparkling form this season and heads into the final grand slam event of 2015 buoyed by an impressive hardcourt run in Cincinnati earlier this month. “Now I’ve got the confidence, I’ve got the matches and I’m actually still feeling really fresh even after this week,” Federer said after beating world number one Novak Djokovic in the Cincinnati final eight days ago.