Semis preview: Will Raonic's offense beat Murray's defense?

Murray: Closing the roof helped my return (3:22)

Andy Murray talks about his quarterfinal win over David Ferrer at the Australian Open. (3:22)

As exciting as it was to anticipate and watch Novak Djokovic clash with Roger Federer once again, the second men's semifinal of the Australian Open probably will be more closely contested. It's certainly a more well-balanced matchup (Friday, live on ESPN/WatchESPN, 3:30 a.m. ET).

Andy Murray, the No. 2 seed, is the best returner in the men's draw, having won 42 percent of his return games. His opponent, Milos Raonic, while seeded just 13th, happens to be the most deadly server and serve-holder. He has won a tournament-best 94 percent of his service games.

What's that they say about unstoppable forces and immovable objects?

But there's this, too: The men have split their six meetings, including 2-2 on hard courts.

Sure, Murray owns a brace of Grand Slam singles titles and an Olympic singles gold medal. That's valuable experience. You could say the same for his four unsuccessful adventures in the final of this tournament. But that's karma as well: Who can forget Murray crying after he lost the 2010 final?

Raonic, by contrast, has been to two Grand Slam semifinals, and so much for that. But he's 25, three years younger than Murray, and barreling into this one with a cannon, a new coach who's taught him to be chill and an undefeated record in 2016. He's also looking to become the first Canadian man to reach a Grand Slam final.

The 6-foot-6 power-server has put himself in this position by continuing to hone his attacking skills. Now, instead of being content to serve big and dictate with his forehand, he is committed to approaching the net. Before his quarterfinal meeting against Stan Wawrinka, Raonic actually won more points at the net than at the baseline,141-138.

The credit for the uptick in Raonic's aggression goes largely to his new partnership with Carlos Moya, whom Raonic hired after Federer lured away his former coach, Ivan Ljubicic. Moya was perhaps the most laid-back of Grand Slam champs (as well as one of the most short-lived at No. 1), so it's easy to see why Raonic says he is a calming influence. What is surprising, though, is clay-court wizard Moya's enthusiasm for the attacking game.

Analyzing why his aggressive tactics have paid off and why he looks so much more relaxed at the net, Raonic said in a recent interview: "It's about a [better] understanding of what you need to do, where you go in certain situations, how not only to finish the points, how to defend a little bit better at the net and how to cover and move better to make the opponent think."

Raonic's problem is that Murray knows how to think; he's one of the better and more inventive among the game's problem-solvers. He's also superb at tracking an opponent's apparent winners and smacking whistling passing shots. He will do all in his power to engage Raonic in rallies and wear him down.

Although Murray wasn't completely satisfied with his game in the early rounds, he felt comfortable by time he was into a fourth set against David Ferrer in the quarterfinals.

"I think today was probably the best match I played," Murray said in his news conference after winning that one in four sets. "At the end of the match, I felt like I was playing some pretty good stuff."

The question hanging over this match will be how much "stuff" Raonic will allow Murray to play, knowing what an enormous advantage Murray has in defensive skills and all-around movement. Raonic will have to make this a slugfest rather than a track meet, and hope that good offense can beat good defense.