The draws have been made for the ATP World Tour Finals, the season-ending tournament, at the O2 Arena in London, beginning on Sunday, 20 November.

World number one Novak Djokovic and British number one Andy Murray have been drawn in the same group, while world number two Rafael Nadal and fourth seed Roger Federer will battle it out in the other group.

David Ferrer and Tomas Berdych are also in first group, with Jo-Wilfried Tsonga and Mardy Fish completing the second group. The top two from each pool, after the round-robin group stage matches, will qualify for the semifinals.

The top seeds - Djokovic and Nadal - were kept apart in the draw, with the same policy adopted for third-ranked Murray and fourth seed Federer, Ferrer and Tsonga, as the fifth and sixth in world rankings, and Berdych and Fish as seventh and eighth ranked.

Before the draw, defending champion Federer admitted it would be a tough tournament with every contestant going in with a chance.

If Djokovic is fit and Murray is fit - which it seems like he is - they will be difficult to beat, the 16-time grand slam champion said. Rafa (Nadal), regardless of how he's going to be, is always a tough customer.

Everybody can beat everybody - I don't feel like (the players ranked) five, six, seven and eight have no chance - I definitely feel like they have a chance to go deep (into the competition).