ESPN experts' X factors for the semifinals

What are the biggest matchups in Sunday night's semifinals (ESPN, 7 ET)? Who are the impact players at the Final Four?

A look at how our experts answered those questions on Saturday:

Mechelle Voepel, ESPN.com columnist

Mechelle Voepel The X factor for North Carolina is LaToya Pringle. She has led the Tar Heels in rebounding during the NCAA Tournament and will try to limit Tennessee's second chances along with giving her own team more of those. Tennessee's X factor is Sidney Spencer, who will have to work hard on the boards but is also needed to hit mid-range and longer perimeter shots.

The X factor for Rutgers is sophomore Heather Zurich's ability to make a few shots, because she is going to get some good looks. LSU's X factor will be the ability to break the press. That was one of the biggest keys for the Scarlet Knights in beating Duke. If LSU doesn't contend with it well, Rutgers will control the game.

Graham Hays, ESPN.com columnist

Graham Hays It's no coincidence that everyone is talking about Kia Vaughn's matchup with Sylvia Fowles in the LSU-Rutgers semifinal. Vaughn doesn't need to shut down Fowles or score 20 points herself for Rutgers to come out on top, but she does need to make Fowles work -- whether matched up in man-to-man or in the middle of a zone -- without forcing C. Vivian Stringer's defense to drain too much energy away from the perimeter.

For the nightcap, it's critical to remember that even though North Carolina won the initial meeting with Tennessee back in late November, Tar Heels coach Sylvia Hatchell wasn't entirely pleased at the success Tennessee had in slowing down the Tar Heels (or that UNC had in slowing down itself). The Lady Vols are a much more cohesive team after a full season of Shannon Bobbitt playing alongside Alexis Hornbuckle, and they're likely going to focus on trying to make the Tar Heels execute in half-court sets. If Bobbitt and Hornbuckle can slow North Carolina's attack, it's a victory for a Lady Vols team that is very dangerous in confined space now that Candace Parker is playing the best defense of her career.

Nancy Lieberman, ESPN analyst

Nancy Lieberman Rebounding also is a key area. North Carolina has grabbed 140 more offensive rebounds than its opponents this season and boasts a plus-11.1 rebounding margin heading into Sunday's game. That equates to a lot of second-chance points, so Tennessee -- which averages 38.2 rebounds per game to UNC's 45.4 boards -- must get on the glass. Nicky Anosike is the only Lady Volunteer with close to 100 offensive boards (98), but UNC has two players with more than 100 (Erlana Larkins has 165, Camille Little 100) and a third not too far behind (LaToya Pringle has 96). Tennessee got outrebounded 43-33 by North Carolina when the teams clashed in Chapel Hill on Dec. 3 (UNC won 70-57), and if the Lady Vols don't close that gap, they will not win. More …

Beth Mowins, ESPN play-by-play

Beth Mowins Rutgers' perimeter speed sets it apart, with Big East Defensive Player of the Year Essence Carson and her high-scoring running mate Matee Ajavon (regional Most Outstanding Player) leading the way. They are very disruptive on the defensive end and both can create their own shots offensively. LSU must find a way to handle the Scarlet Knights' trademark "55" defense -- a full-court, man-to-man pressure defense -- to stay close. More …

Kara Lawson, ESPN analyst

Kara Lawson In March, everything centers around great players and their ability to uplift their team. Sylvia Fowles is the reason LSU is here. She has played big and has to keep putting up those types of numbers. LSU's role players also have to keep making plays. [Point guard] Erica White must be aggressive in transition. But this is all about Fowles. She's the best center in the country. She has surpassed [Ohio State's] Jessica Davenport and [Oklahoma's] Courtney Paris. If I had one pick for a post, I would choose Fowles.