FACTBOX: Masters Cup tournament

SHANGHAI (Reuters) - Key facts about the men's season-ending Tennis Masters Cup beginning in Shanghai on Sunday:

* The tournament involves the top eight players in the Champions Race, based on results over the season, and offers a total of $4.45 million in prize money.

* World number one Roger Federer will be bidding for his fourth Masters Cup title after winning in 2003, 2004 and 2006.

* The Swiss became the first man since 1999 to win three season-ending championships after beating American James Blake in last year's final in Shanghai.

* Pete Sampras and Ivan Lendl share the record for the most titles at the ATP Tour's prestigious season ender with five apiece.

* Federer and Spain's world number two Rafael Nadal booked their places in Shanghai back in July. Frenchman Richard Gasquet secured the eighth and final spot at the weekend.

(Compiled by Alastair Himmer)