LONDON - A scientist from Northwestern University in Illinois has claimed to have solved the debate over who is the best male tennis player of all time.

The disappointing news for disciples of Roger Federer and Rafael Nadal, however, is that Filippo Radicchi's painstaking number-crunching of 133,261 matches played since 1968 suggests that American Jimmy Connors is the greatest of them all.

Federer, who since 2003 has claimed a record 16 grand slam titles, comes in at number seven and Spain's Nadal, the current world number one and nine-times major winner, lurks down at number 24, below the likes of Eddie Dibbs and Tom Okker.

Connors, a pugnacious left-hander who was No. 1 in the ATP rankings for 160 consecutive weeks from 1974-77 and won a record 109 titles including eight grand slams, topped the list ahead of his former rivals Ivan Lendl and John McEnroe.

Pete Sampras, whose record of 14 grand slam titles was eclipsed by Federer, is one place below the Swiss at eight while Swedish great Bjorn Borg only just scrapes into the top 10.

Collecting ATP data from the past 43 years, Radicchi believes his system using a "diffusion algorithm" outperforms other methods used to try and end the "greatest of all time" or GOAT debate that splits tennis fans.

"We performed a complete analysis by determining the best players on specific surfaces as well as the best ones in each of the years covered by the data set," Radicchi said.

"In this particular ranking system, it's more important to win a single match against a very good player than many matches against not-so-good players."

Best Player

Explaining Connors' position as the best player, Radicchi said his system rewarded the American's longevity which enabled him to continue playing until well into his 40s.

"Among all top players in the history of tennis, Jimmy Connors has been undoubtedly the one with the longest and most regular trend, being in the top 10 of the ATP year-end ranking for 16 consecutive years," Radicchi said.

While Nadal has dominated on claycourts for the past six years, Argentina's Guillermo Vilas is ranked as the best of all time on the surface, according to the study, while Connors, surprisingly, tops the grasscourt list with Federer third.

American Andre Agassi is ranked the greatest player on hard courts, with Federer down in fifth behind Connors, Lendl and Pete Sampras.

For those crying foul about the absence of Rod Laver, the last player to win the calendar grand slam, the Australian was identified as the best between 1968-71, when the ATP rankings system was not yet established.