Roger Federer marches on at ATP Finals as battle over Davis Cup’s future goes on

• Federer defeats Kevin Anderson 6-4, 6-3 to top his group
• Davis Cup could merge with new ATP Cup to resolve rowTennis might be fighting for its soul but Roger Federer remains its beating heart.On a day when it was learned that a merger of the revamped 118-year-old Davis Cup and the new ATP Cup – which will be held within six weeks of each other at the end of next year and the beginning of 2020 – is one solution being considered to break the impasse that has gripped the s