When will Tsonga finally break through?

The ruling class of men's tennis continues to shrink. Last year, we talked about the big four -- Novak Djokovic, Rafael Nadal, Roger Federer and Andy Murray. In 2012, after Murray's up-and-down spring, we've drifted toward the big three. Now, in light of Federer's poor showing against Djokovic at the French Open, it might soon be down to the big two. After all, Rafa and Novak have played each other in the past four Grand Slam finals.

We've been asking it for a while now, but with Wimbledon beginning on Monday, it's time to ask it again: Can anyone break the stranglehold these men have on the majors? Here's a list of candidates, from most plausible to least. I'll start by saying that all of them qualify as long shots rather than good bets.

Jo-Wilfried Tsonga

The question is: Was Jo's excellent performance against Djokovic in Paris, where he held four match points, a sign of progress against the top two, or was the fact that he blew those four match points a sign that he's still too fragile to beat them at the majors? Wimbledon, played on a surface Tsonga likes, should help give us an answer. He beat Federer here last year.

Tomas Berdych

He also beat Federer here, as well as Djokovic, on his way to the 2010 final. And despite a disappointing loss to Juan Martin del Potro at Roland Garros, the big Czech has progressed in 2012. Oddly, he has a lot of confidence when he plays Andy Murray, but less when he plays del Potro. I can see him beating anyone -- except the top two.

Milos Raonic

Here's your 2012 version of the guy that no one wants to face early. Raonic, the ATP's ace leader, has lost two third-set tiebreakers to Federer already this season. He should feel at home on grass, provided he's not slipping on it, as he did last year at Wimbledon, where he had to retire with a season-ending injury. But I would like him better against guys like Djokovic and Murray, if they didn't have such good returns. I would also like Raonic better if I didn't think he was still in the process of learning how to lose big matches -- which is what most players have to do before they can learn how to win them.

Others to watch

John Isner: The serve is there; the speed isn't. Aside from that marathon you may have heard about, he hasn't done much at Wimbledon

Grigor Dimitrov: He has the flash for grass, but his backhand, as nice as it looks, is a liability.

Bernard Tomic: Crafty and annoying, and a quarterfinalist here in 2011, it's never clear how much he wants to win.

Marin Cilic: There have been signs of life this year, and a recent title in Queens. Still, for now, he's a level below the second-level guys.

Feliciano Lopez: That lefty hook serve makes him a tough out on grass.

David Nalbandian: He's usually been OK in front of a hostile audience in Davis Cup. He may face another one in London. Has a player ever had to make bail to play at Wimbledon?