Why thinking too much can be bad for you

By Ian Leslie

It was the fifth set of a semi-final at last year’s US Open. After four hours of epic tennis, Roger Federer needed one more point to see off his young challenger, Novak Djokovic. As Federer prepared to serve, the crowd roared in anticipation. At the other end, Djokovic nodded, as if in acceptance of his fate.

Federer served fast and deep to Djokovic’s right. Seconds later he found himself stranded, uncomprehending, in mid-court. Djokovic had returned his serve with a loose-limbed forehand of such lethal precision that Federer couldn’t get near it. The nonchalance of Djokovic's stroke thrilled the crowd. John McEnroe called it “one of the all-time great shots”.