1, 2, 3, 4?

We're down to the final four at this year's Australian Open, and for the fourth time since 2008 it'll be a familiar set of faces battling for the men's crown. It's the top men still left standing as we enter the semis -- their rankings and opponents have been shuffled around a bit, though, and that could lead to a few more sparks than we might otherwise expect.

Rafael Nadal and Roger Federer kick off semifinal action on Thursday, the first time they've met before the championship round of a Major since 2005. Of course, the Spaniard leads the pair's overall head-to-head, winning nearly two-thirds of their meetings, but Roger holds the slight edge on hard courts and won their last battle at the 2011 year-end finals.



There were some clouds over their heads coming into this tournament -- Nadal struggled with a knee injury and the Swiss withdrew before his semi in Doha -- but both have been dominant in their matches down in Melbourne. Though Rafa lost a set to Tomas Berdych in their quarterfinal on Tuesday, neither have given any of their opponents much of a look so far this fortnight. Then again, neither have been given any challenges quite as tough as each other to date.

That should change on Thursday, though. The last time the two met in Australia -- in that amazing 2009 final -- we were treated to an epic four-hour, twenty-minute, five-set thriller which earned Nadal his first hardcourt Slam. But he hasn't made it back to the semis since, and something tells me we might be in for a different result this time around. Roger ended 2011 with one of the hottest streaks on Tour, and having gone almost two years now without a Major title, you have to think pure hunger will drive him to a win. And if he gets it, there may be no stopping him.

Of course there will be the other semifinal survivor to contend with. On Friday defending champion Novak Djokovic will face last year's runner-up Andy Murray in a rematch of the 2011 final, only one round earlier. It'll be the pair's eleventh career meeting, with the world #1 currently holding a 6-4 edge, but they're dead even on this surface. Somewhat surprisingly, though, this will be only their second battle at a Slam, and these days it's the Serb who has all the experience there.



But the Scot might not be in for a total repeat of last year's thrashing. Murray had the lead on Nole in the Cincinnati finals this past August, and probably would have won the match even if Djokovic hadn't retired. And he's coming off a title in Brisbane -- along with the three Asia trophies he earned to end last season -- so he's arguably riding the other big momentum wave in the sport. Meanwhile, after his amazing run last year, I'm frankly a little surprised Nole has any juice left in him. But both have been equally dominant so far Down Under, and there's no telling what they'll be capable of while playing at their best.

All four of these guys have been at the top of the game for so long, and are so familiar with each other's games, that there's no way to say for sure who'll come out on top. Of course, I grudgingly picked Murray to ultimately walk away with the title, and even with the depth of experience left in the draw, that very well could still happen. And the next few days of play could set the stage for an even bigger shake-up at the top of this sport over the next few months.