WIMBLEDON, England -- Even before the tournament began, the No. 15 was the elephant in the room.
"The focus is on the first round," Roger Federer said two days before he hit his first ball. "Trying to regain my Wimbledon crown stands over trying to beat Pete's record right now. Once I come down to the semifinals or finals, then hopefully that's going to start creeping into my mind."
For about a month, Federer and Pete Sampras had been tied atop the all-time tennis leaderboard with 14 Grand Slam singles titles.
After he reached the semifinals, Federer acknowledged that No. 15 "would be writing in the history books of tennis."
And than he cautioned: "It's not there yet. Still far away. Many points, many serves, many forehands. We'll see."
It's been a long journey, stretching back to six years ago, when he won his first career major here at the All England Club, but now we see No. 15. What does it all mean? We asked some of the experts.
Serena Williams, 10-time Grand Slam champion: Oh, I mean, that is amazing. Fifteen, you know, it's incredible. I definitely think when you speak of the greatest, you have to include Roger Federer. He has a lot of years left.
Rod Laver, 11-time Grand Slam winner: It's an unbelievable effort to have 15 Grand Slam titles. I've always thought that you're the best in your era. That to me is a pretty good compliment to your game, to your tennis, over your career. You know, if Roger gets to 16, 17 Grand Slams, you know, people in the press are the ones that are wanting to say it: `Who's the best ever?'
My thought is that if you're the best in your era, you know, and you probably don't even know who Bill Tilden is. It's hard for anyone I think to come out and say who's the best ever. It's like boxing. Who's the best ever in boxing? I don't know anybody's come up there. To me it's an era.
Bud Collins, ESPN analyst: Winning 15 majors is a tremendous landmark, but I don't necessarily think Roger is a better player than Pete. I'm one of those people who thinks Pete played better competition in his day. [Boris] Becker, [Andre] Agassi, [Jim] Courier, [Ivan] Lendl -- those were some great players. As far as Laver goes, you can't compare; different eras, different equipment, different surfaces. Laver won 11 majors? If he'd played those five years in his prime he would have put up some more, even with [Ken] Rosewall there.
Boris Becker, seven-time Wimbledon finalist: After he won in Paris everybody was calling him the best player ever, including me. I hate to compare the Lavers, the Borgs and the McEnroes to the Federers, but in my opinion, yes, he is the greatest. And he's only 27 years old. He's going to add many more Grand Slam titles.
John Newcombe, seven-time Grand Slam champion: The question isn't how many Slams Laver would have won, it's how many would Ken Rosewall have won if he wasn't excluded from the Slams for 11 years. After Laver won his Grand Slam in 1962, it took him two years to beat Rosewall after he turned pro. Federer lost to Rafael Nadal three times in an eight-month span in Grand Slam finals. He's one of the greatest ever, along with Laver, Rosewall and [Bjorn] Borg. For that, you can't go past the fingers on one hand.
Patrick McEnroe, U.S. Davis Cup captain: If three out of the four majors were played on grass these days, how many would Sampras have won? I'll say this: Federer is the best player I've ever seen. I never saw Laver, except on tape. Fed has it all -- longevity, the major titles and his greatness in the game. And I think winning the French validates him. He's the best combination of offense and defense. You have guys who are offensive-minded, like Sampras, Becker, my brother and [Stefan] Edberg. Then you have the defenders like Rafa Nadal and [Mats] Wilander. Federer gives you both.
John McEnroe, seven-time Grand Slam champion: That's one of those questions there's no answer to. It's just a matter of opinion, and lots of people have different opinions. Rod Laver was my idol, and he won two Grand Slams. So it would be hard to say anyone is better than that, because I don't think you will see guys even win one Grand Slam. Roger has won on all surfaces. I think Pete Sampras may be a better fast-court player than Roger Federer, but all around I think Roger is the greatest player I have ever seen.
Pam Shriver, ESPN analyst: There are some people who say you can't compare eras, no matter what. Bill Tilden to Don Budge to Rod Laver to Pete Sampras. I think he's the greatest of all time. I think nobody in men's game -- maybe women's, too -- has won two of the four majors five times in a row. That's gaudy. The consecutive 20 semifinals. There are statistics and so on and so forth, but that's something that makes us that played the game go, "Oh my God."
Pete Sampras, 14-time Grand Slam champion: I really don't feel like Roger feels that urgency as I felt in my time at Wimbledon -- especially playing Goran [Ivanisevic], [Richard] Krajicek, Becker -- these big servers, guys that can come in and sort of take your time away. I think Roger feels comfortable and relaxed, and he knows he is the best player on grass. I look at [Novak] Djokovic, [Andy] Murray, Nadal and Roger as those four great players. And [Nos.] 5 through 15 are sort of in the same boat. That's the way I sort of see the game today. The player ranked 30 today is probably better than the guy ranked 30 in my time, so it is maybe a little bit deeper. But I don't see it as sort of dominant with as many Grand Slam champions on top.
Martina Navratilova, 18-time Grand Slam champion: It happened so fast. First, we're talking about will he ever win another Grand Slam and why can't he win the French, and now he's about to break the record. How do you compare Federer to Laver? Navartilova to [Billie Jean] King or [Margaret] Court? You don't. We don't need to be talking about this until he hangs them up.
Novak Djokovic, 2008 Australian Open champion: He's playing most of the shots perfectly. If you look at his game, it's an all-around game, that many people are saying that it's one of the greatest of all times. I think after five years of dominance, it's just amazing to see him again motivated to play well and win more Grand Slams. You've got to give him credit for that.
Mats Wilander, seven-time Grand Slam champion: Yes, he has the world record, but he's never going to be the greatest player of all time. It's not fair to the Rod Lavers of the world. He won two Grand Slams, all four majors in two different years, and he was not allowed to play for the five years in between. He could have won, what, 25 Grand Slams. Yes, 15 [majors] is always going to beat [Sampras' 14]. And Laver played three of his four majors on grass and Federer has won on all surfaces now. But, his not-great record against Rafael Nadal is a gray cloud over his career. I'd like to see him beat Nadal in a Grand Slam semifinal or final.
Venus Williams, seven-time Grand Slam champion: You know, just his confidence on the court is amazing. There's a million things that he does great that any player can learn from -- me included.
Lleyton Hewitt, two-time world No. 1: Every record that he's equaled or broken is amazing in itself. It's hard enough just to do it for a couple years. He's been able to do it for five or six years now in a row. Something like 20-odd Grand Slam semifinals in a row, which is a little bit unheard of. Physically, you've got to be extremely strong to be able to do that, but obviously mentally as well.
Brad Gilbert, ESPN analyst, former coach of Andre Agassi and Andy Roddick: The guy is 27 years old, and he's probably thought about 20 [Grand Slams] or just getting better. He still thinks he has a lot more to do. Maybe the next number is 22 -- Steffi Graf -- that's a pretty good number to chase. With Fed, if he's still feeling it in 2010, nothing's out of the question.
Greg Garber is a senior writer for ESPN.com.