Roger Federer admits his bid to retain the Wimbledon title will be driven by the prospect of equalling Pete Sampras's record of seven singles' titles at the All England Club. Federer will walk onto Centre Court today for his first round match against Colombia's Alejandro Falla with Sampras firmly on his mind at the start of a potentially historic fortnight for the world number two. Sampras has been the finest exponent of grass court tennis in the Open era, but the American conceded last week that Federer has a great chance to shatter his Wimbledon record.The 28-year-old, who announced his arrival as a force at Wimbledon with a victory over Sampras here in 2001, has already beaten Sampras's record of 14 grand slam singles titles and knows it would be remarkable achievement to draw level with the American's tally of All England Club titles.Although Federer's phenomenal record at Wimbledon was enough to guarantee him the number one seeding, ahead of world number one Rafael Nadal, he arrives in south-west London with serious questions over his form.By his own high standards 2010 has been disappointing year for the Swiss, who has failed to win any of his seven tournaments since beating Andy Murray in the Australian Open final in January.Federer' run of 23 successive grand slam semi-final appearances was snapped at the French Open and he even lost for just the second time in 78 matches on grass when Lleyton Hewitt beat him in the final at Halle last week.Yet Federer insists his recent struggles have not affected his preparations for Wimbledon and he expects to make another long run in the tournament.