PARIS – Roger Federer will bid to back up his title from a year ago when he heads the field at the final event of the regular ATP season, the Paris Masters, starting on Monday.The Swiss world No 1 stormed to victory at the Bercy Arena a year ago against outsider John Isner in the final, beating Juan Martin del Potro in the quarterfinals and putting out Rafael Nadal in the semis.Federer is focussing on another end of season sprint, but one without a pause as the eight-man World Tour Finals begins in London a day after the Paris final.That scheduling wrinkle may come back to haunt the ATP as the organisation shortens the 2012 season by a fortnight, eliminating the rest and preparation week before the round-robin end-of-season classic.With Nadal missing after ending his campaign early due to the knee injury which has kept him off court since June, Federer leads a pack trailed by second seed Novak Djokovic and US Open winner Andy Murray.Djokovic beat Murray for the Shanghai title this month, with neither man playing since.Murray withdrew from the Swiss Indoors, claiming a back niggle, to the dismay of organisers faced with his second pullout in as many years.Federer is trying to avoid pressure as the race to the year-end No 1 ranking goes down to the wire with Djokovic pushing hard and results in Paris a key to any possible movement in the table."I have to think day by day. It’s simple, it’s pretty routine, but it’s my only way to handle these next couple of crazy weeks,” said the Swiss.With all 16 seeds getting first-round byes, lesser contenders will begin play, with French players Benoit Paire, Paul-Henri Mathieu – both defeated by Federer in Basle last week – and Michael Llodra receiving wildcard entries.Spain’s David Ferrer takes the fourth seeding ahead of Czech Tomas Berdych, and a trio of London contenders – France’s Jo-Wilfried Tsonga, del Potro and Serb Janko Tipsarevic.Others who will be battling for the last two spots in the London field are Spaniard Nicolas Almagro and France’s Richard Gasquet.Agencies