LONDON — No one has come close to cracking the riddle of beating Novak Djokovic on an indoor court for more than three years and Kei Nishikori became the latest player on Sunday to discover just how difficult it is to solve that puzzle.
Djokovic began his bid for a record fourth successive title at the ATP World Tour Finals with a brutal yet awe-inspiring 6-1 6-1 hammering that left Nishikori in a daze.
"No question, it felt like the best tennis I played this year," the 28-year-old Serb told reporters.
"I was at my best and it was an incredible performance.