
Switzerland’s Roger Federer jumps for a serve to Japan’s Kei Nishikori during their singles ATP World Tour tennis finals match at the O2 arena in London, Tuesday, Nov. 11, 2014. (AP Photo/Alastair Grant)
Switzerland’s Roger Federer jumps for a serve to Japan’s Kei Nishikori during their singles ATP World Tour tennis finals match at the O2 arena in London, Tuesday, Nov. 11, 2014. (AP Photo/Alastair Grant)