There have been two first-time Grand Slam winners in the last 2-1/2 years on the ATP tour - Andy Murray, who broke out at the US Open in 2012, and Stanislas Wawrinka, who did likewise at the Australian Open last month.
It's the first time there have been two that close together in five years, since Novak Djokovic won his first in 2008 and Juan Martin Del Potro his only (so far) in 2009. Prior to that, you have to go back to 2003, when Juan Carlos Ferrero, Roger Federer and Andy Roddick each won his first in succession at the French Open, Wimbledon and the US Open, respectively.
The days of Rafael Nadal or Federer winning every single Grand Slam event are behind us; and excitingly so. While their rivalry, which was as compelling a matchup as the men's game has perhaps ever seen, provided some amazing moments and thrilling finals, it grew stagnant over time, because seemingly every event seemed like it was just 126 guys going through the motions in anticipation of another Rafa-Roger final.
Novak Djokovic was the first to disrupt the tandem on a regular basis, and a healthy Murray followed suit. Having multiple players in the field, each with a legitimate shot to win any tournament, including the Big Four, is called parity, and it's the best thing to happen to the men's game since Nadal first rose up against Federer.
Take a look at the other sports leagues in the United States. The NBA is ruled by the two-time defending champion Miami Heat, featuring the hands-down best player on earth in LeBron James. This season, only one other team in Miami's conference, the Indiana Pacers, has a chance to knock the Heat out of the playoffs, which means the first two rounds of the post-season, about two weeks worth of televised games, are virtually meaningless.
Major League Baseball has degenerated to a case of the haves versus the have nots over the past decade. Teams willing to spend massive amounts of money - notably the New York Yankees, Philadelphia Phillies and Boston Red Sox - are always among the contenders for the World Series. Teams who have themselves on a budget - the Kansas City Royals and Houston Astros of the world - have virtually no shot to compete for the playoffs, and everyone knows it from the opening day of the season.
Then there's the NFL - by far America's most popular sport. Nine different teams have won the past 10 Super Bowls, and ratings are through the roof for every game on every night of the week for four months. Why?
Parity. Every game matters, every game has potential for an upset, and every team has players that have become familiar names to the fans. Parity can make tennis more appealing to the masses. A few years ago, it was breaking news one night at the Australian Open solely because Federer was down two sets to love in the first round. He didn't lose the match, but the fact that he was actually trailing by two sets was enough to warrant a buzz.
Murray's two wins at the US Open in 2012 and Wimbledon last summer were enormous to the sport because it reinvested the fan base of the country that not only invented tennis, but is arguably the most passionate about it.
Wawrinka's win last month in Australia was perhaps even more enormous because it was completely out of left field, and because he didn't luck into the title, he beat No. 2 and No. 1 in the world to seize it.
It's hard to imagine anyone but Nadal winning at Roland Garros in three months, but that day will eventually come to. However, parity is back in the ATP, and that will make for an exciting rest of the year, as men's tennis cycles toward a time when anyone can win and anyone can be beaten.