Given Roger Federer had begun 2017 ranked at No 16 and without a major win since 2012, this has been quite the turnaround. Tony O'Brien / Reuters
Given Roger Federer had begun 2017 ranked at No 16 and without a major win since 2012, this has been quite the turnaround. Tony O'Brien / Reuters

ATP World Tour Finals: Federer looking good to end excellent season on a high with one eye on 2018