Nadal really got to Federer's head during the Australian Open final last weekend, as he prevented Federer from equaling Pete Sampras' record of 14 Grand Slam titles in another five-set (7-5, 3-6, 7-6, 3-6, 6-2) thriller between the two rivals. Despite the many other epic matches played between the two, this was their first Grand Slam final meeting on a hard court.

The match was not even close to being as good as the historic Wimbledon final last year (widely considered to be the best tennis match ever played), when Nadal prevented Federer from winning his sixth-straight Wimbledon title. And although any match between Federer and Nadal is going to be exciting by definition, this match slid to a disappointing low as it became more and more obvious toward the fifth set that Federer's nerves were getting the better of him.

Clearly, Nadal takes Federer out of his comfort zone whenever the two meet, as Nadal's tremendous defensive ability forces Federer to go for a lot more on his shots and thus miss a bit more. But I think there's another reason why Nadal is such a tough opponent for the former world No. 1, and that's all in the mental game.

In tennis, match-ups are everything. Sure, there's the pressure of capturing his 14th Grand Slam title and equaling "Pistol Pete's" record, but what troubles Federer the most is the enormous amount of top-spin Nadal gets off the forehand side that he sends kicking high to Federer's backhand, and hitting a one-handed backhand at shoulder level is just as painful to do as it is to watch. Federer is known for staying in control under pressure, but he also has huge winning records against most of his opponents, and that gives him re-assuring confidence. Against Nadal, he has a losing record of 6-13-five of those losses coming in Grand Slam finals-and that creates a vicious cycle that is mentally hard to get out of.

Let's go back in time to 2007-Federer had consecutive winning streaks in every Grand Slam tournament except the French Open. He was setting countless records in tennis history, and had been the world No. 1 player for the last three years. Nadal, on the other hand, had a two-win streak at the French Open, but had lost twice to Federer at the Wimbledon finals, had a mediocre serve, and lacked consistency in his game. He was very far from challenging Federer's dominance.

In just two years, Nadal has overtaken Federer to become world No. 1, and proven himself to be more than just a "one surface wonder." He's even got a new outfit now, finally getting rid of those capri shorts, though I was sad to see the sleeveless shirt go. The two men have not only established one of the best rivalries of all time, but have also done so much for tennis and are respected by fans for being charismatic, well-behaved, and very humble. After his devastating loss, Federer started choking up at the awards ceremony—only to find Nadal giving him a friendly hug, saying in front of the crowds, "Remember, you are one of the best players of the history and you are going to improve the 14 of Sampras."

Some people believe that Nadal's recent wins over Federer show that tennis will soon be a one-man show again, this time with Nadal in the driver's seat. However, it's just too early to say whether Nadal will ever be as dominant.

Now is a good time for Federer to regain some lost ground and add some heat to the rivalry, and the best way to do that is to try and dethrone Nadal at Roland Garros this summer. Capturing his 14th Grand Slam title on clay would also be momentous-even Pete Sampras never managed to win the French Open. Nadal started his dominance on clay, and if Federer can steal the throne it would give him some much needed confidence, setting the stage for another epic Wimbledon showdown.