Day 4: Murray v Nadal

Sue Barker introduces further live coverage of the ATP World Tour Finals from the O2 Arena in London. Andy Murray faces Rafa Nadal.

The likes of Bjorn Borg, Ivan Lendl, John McEnroe, Pete Sampras and Andre Agassi have all won this season-ending event, but the most successful player in its history is Roger Federer. The Swiss superstar is back again this year, aiming for a record seventh title in his 14th consecutive appearance at the season's finale.

Match commentary and expert analysis comes from Andrew Castle and Tim Henman.