This week's tennis: WTA curtain call and the race for the o2

In a few weeks time, London's o2 will host the second biggest UK based tournament, the ATP finals. But this week it is the turn of the world's top eight women, who take to the court in Istanbul. The eight participants are split into two groups of four, with the top two from each progressing to the semi finals.

And as is often the case with Women's tennis these days, the field is wide open with the bookies seemingly unable to call it. That said, Petra Kvitova and Victoria Azarenka are both narrow joint favourites. Kvitova, who won Wimbledon this year to record her first Grand Slam title faded away somewhat in the latter part of the season, but bounced back well with a recent win at Linz.

Azarenka perhaps under performed in the majors, but managed a pretty solid season otherwise, the highlight of which being a straight sets win over Maria Sharapova in Miami

Sharapova herself is third favourite having moved back up to number 2 in the world. She is the only player in the field to win the tournament having defeated Serena Williams in 2004. World number 1 and last years runner up Caroline Wozniacki is only considered 4th favourite despite a typically consistent season.

The other two major winners, Li Na and Sam Stosur, who won the French and U.S. Open respectively, are considered outsiders. Both have been inconsistent since their big wins, and as a result Vera Zvonareva and Agnieszka Radwanska are more heavily fancied.

This weeks ATP tennis is less of spectacle, with just a couple of 250 tournaments taking place. Even so, the Erste Bank open in Vienna could still have a bearing on who takes to the court in London next month. Current world number 9 Jo Wilfred Tsonga is the only player in the mix to play. Should the Frenchman win he will move in touching distance of Mardy Fish above him. With Tsonga's home Masters, on the fast indoor hard courts of Paris, still to come, a win in Austria will put him in serious contention.

Meanwhile, 44 year old Thomas Muster will retire for the second time after he bows out in Vienna. The former Roland Garros champion made an unlikely comeback in 2010, but currently sits at 1078 in the rankings.