The Swiss player, who goes into the Australian Open which starts on Monday as one of the hottest favourites in the tournament's 100-year history, has not lost to anyone inside the top 10 for more than a year.
Unlike the eras of John McEnroe and Jimmy Connors, Boris Becker and Stefan Edberg, and Pete Sampras and Andre Agassi, Federer is unrivalled at the top, with no one having been able to get the better of him on a regular basis.
With Andy Roddick, Lleyton Hewitt and Marat Safin trying to bridge the gap, however, Federer says a rivalry with one or more of the others could help him to improve even more.
"I'm playing so well right now but maybe a rivalry could lift my game," he said.
"If I started to lose to the number two, three, four, it would definitely be interesting."
Last year, Federer beat Safin in the final at Melbourne Park, overcame Roddick to win Wimbledon and triumphed over Hewitt to clinch the U.S. Open.
"Lleyton, Andy and Marat all have the ability to beat anyone on a given day and win tournaments," he said.
"Every one (of them) played a grand slam final last year. I think the favourites are those three and (Andre) Agassi.
COACH ROCHE
"Agassi doesn't play as many tournaments as everyone else but he is always good at Grand Slams, and then you have (Tim) Henman and (Carlos) Moya."
Having gone through 2004 without a coach, Federer has teamed up with former French Open champion Tony Roche, who will work with him on a part-time basis.
Roche helped Ivan Lendl and Pat Rafter to several grand slam titles and Federer said the Australian's presence gave him more confidence.
"Last year I had to fight with the expectations and the comments of people telling me that I don't have a coach, that that was a totally wrong decision, and those things put the pressure on me," he said.
"Now one year without a coach, I feel very confident. I know that I can handle it myself. Plus now with the help of Tony...things couldn't be any better."
While Federer said Roche had a tough job to improve his results, he said it would be his own fault if he faltered in the coming months.
"I think the experts, and me and Tony, we all know it's not his mistake if my ranking drops. Eventually it will drop. I can't stay number one for 50 years, you know."
