When Roger Federer reaches a tournament final, he doesn't lose. Nobody knows that better than Andy Roddick. The unflappable Federer won his 22nd straight final on Sunday, beating the exasperated American 6-3, 7-5 for the Cincinnati Masters championship and his ninth overall title this season.
Federer improved to 10-1 against Roddick, who tried every tactic but still came up short. Federer has won the last six times they've met, including the last two Wimbledon finals. The world's top-ranked player for the last 81 weeks, Federer heads into the U.S. Open fit, relaxed and on a roll. He took time off after winning his third straight Wimbledon, looking to recharge and rest a sore foot.

　　文中的on a roll表示"连连获胜中；连续交好运中"。If someone is on a roll, they are successful or lucky for a short period of time. 例如：When he won one game after another, it was obvious he was on a roll.（当他赢得一场又一场比赛时，很明显他正在连续交好运。）