The keys to St. Louis victories?

The PG battle between Deseree Byrd and Danielle Robinson could decide Louisville-OU. US Presswire/Icon SMI


What are the X factors in Sunday's national semifinals? ESPN.com's panel of experts breaks down which key factors could determine who moves on to the NCAA title game. (And click here to see which teams they picked to win.)

Louisville vs. Oklahoma (ESPN, 7 p.m. ET)


From the moment Chauntise Wright went down with a season-ending injury before the first game of the campaign, Louisville has faced questions about how it stacked up in the post. So it's fitting that having reached the Final Four for the first time in program history, the Cardinals find their biggest test waiting for them in St. Louis.

Louisville has a mixed record when it comes to slowing elite post players, but it's not a record trending in the right direction. Xavier's Ta'Shia Phillips managed just four points and eight rebounds in 29 minutes in a Louisville win early in the season, but the Big East's two best big players had more success. Connecticut's Tina Charles averaged 19.5 points and 12.5 rebounds in two routs, and Rutgers' Kia Vaughn averaged 16 points and 10 rebounds in her team's two close losses against the Cardinals, one in Louisville and one on a neutral court in the conference tournament.

As impressive as the team's run through the tournament has been, going on the road to beat LSU in Baton Rouge in the second round and beating everyone's favorite Final Four pick, Maryland, in a regional final, it hasn't faced a go-to post player. Baylor didn't have Danielle Wilson in the Sweet 16, and Maryland's threats were on the wings and the perimeter (although Terrapins forward Demauria Liles managed 17 rebounds).

All of which means that whatever defensive alignments Louisville coach Jeff Walz devises to counter Courtney Paris, Keshia Hines and Monique Reid need to be available. Hines, a sophomore, and Reid, a freshman, combined to average 9.5 fouls per 40 minutes this season. But in the last three rounds of the NCAA tournament, they combined to average nine points, 10.3 rebounds, 42 minutes and just four fouls. -- Graham Hays


Courtney Paris' performance. She has to be sharp from the get-go -- in other words, she must finish shots, which she didn't do well in the first half against Purdue in the regional final. The other element is somewhat less in her control: how the game is called. She can't afford to be in foul trouble, and the wide range in how officials call the interior in the women's game means anything is possible. She has to figure that out quickly and adjust to whatever it is. Which is much easier said than done.

Angel McCoughtry and Candyce Bingham have proved largely unstoppable -- they are going to get their points and rebounds. What the Cardinals did against Maryland, though, is get 24 points off their bench. Oklahoma can't allow that, which means the Sooners have to defend with the same kind of energy as they did in the second half against Purdue. Oklahoma also has to come out on top in the matchup of sophomore point guards Danielle Robinson and Deseree' Byrd. -- Mechelle Voepel


The point guard matchup between Oklahoma sophomore Danielle Robinson and Louisville sophomore Deseree' Byrd might have the biggest impact. In Tuesday's regional final victory over Purdue, Oklahoma was a totally different team in the second half when Robinson was under control and making good decisions. She ranks among the country's elite point guards. Byrd -- who didn't play point guard in high school or even last season -- also has been very composed at the point, especially after having come into a pressure-packed postseason with a bit of a question mark. She has held up incredibly well. Whichever guard wins this matchup will give her team the X factor. -- Beth Mowins


Oklahoma coach Sherri Coale said it after the regional final win over Purdue: When Whitney Hand makes a 3-pointer, the Sooners come alive. They truly are a different team with a different energy when Hand's shots find the bottom of the net. Tuesday was the perfect example. Hand, despite playing hard, didn't score in the first half, and Oklahoma trailed Purdue by five. The freshman hit three 3-pointers after the break, and the Sooners won the second half by 11.

The health of Amanda Thompson's foot is also something to watch. The junior, a starter most of the season, gave the Sooners a fairly active and productive 12 minutes against the Boilermakers after just a three-minute stint a game earlier against Pittsburgh. A healthier Thompson is one more key weapon at Coale's disposal. -- Charlie Creme

Freshman jitters could have the biggest impact. Will Oklahoma's Whitney Hand hit shots from outside? Will Louisville's top rookies have the necessary poise to pull the upset? -- Rebecca Lobo

Stanford vs. Connecticut (ESPN, 9 p.m. ET)

Nnemkadi Ogwumike. In a bit of a gross oversimplification, Stanford beat Connecticut in the Final Four last season because its backcourt withstood the Huskies and the frontcourt outplayed them.

How the former plays out this season is an X factor in its own right -- as well as Jeanette Pohlen, Rosalyn Gold-Onwude and Jillian Harmon are playing, the Cardinal aren't the same on the perimeter without Candice Wiggins and JJ Hones. No team would be without those two. But on the latter side of the equation, the Cardinal's frontcourt is better now than it was entering the semifinals last season. And depending in part on how well Ogwumike, a 6-foot-2 freshman forward, plays in her Final Four debut, it might be significantly better.

Just as Wiggins' two 40-plus-point explosions in last season's NCAA tournament overshadowed Jayne Appel's 33-point, 12-rebound gem in the opening round, Appel's performance for the ages this season against Iowa State (46 points) makes it easy to overlook another rising star's line from the postseason.

Against a good San Diego State defense on that team's home court in the second round, Ogwumike put up 27 points and 13 rebounds. That was the fifth time in Stanford's last 13 games that Ogwumike held or shared the team lead in scoring. In fact, far from shrinking or tiring in her first postseason, she's averaging 15.1 points and 8.4 rebounds in the past seven games (Pac-10 tournament and four rounds of the NCAA tournament).

Between Appel's ability to pass out of the post and Kayla Pedersen's range that now extends consistently beyond the 3-point line, Stanford's frontcourt was already tough enough for opponents to defend. If Ogwumike -- who at five offensive rebounds per 40 minutes is right on the heels of both Appel (5.3) and Connecticut's Tina Charles (5.5) -- plays like she has of late, it's a bad matchup for a Huskies team that has occasionally shown a tendency to struggle against frontcourts with multiple top-tier talents. -- Graham Hays


Geno Auriemma has said all year that as long as Tina Charles plays well, UConn will not lose. And that's because when you have a post with the ability to be nearly automatic when she gets the ball where she wants it, everything else falls into place a lot easier.

Charles makes herself difficult to guard, and her confidence is very obviously higher this season. She took it personally that the Huskies lost in the NCAA tournament in her freshman and sophomore seasons. She was honest with herself about how she didn't play as well as she was capable in those losses. All this season, she has kept it in mind not to repeat that. -- Mechelle Voepel


Stanford's Kayla Pedersen. UConn's Tina Charles and Stanford's Jayne Appel will balance each other out a little bit. But if there's one thing Cal tried to expose with Connecticut, it's the Huskies' lack of post depth. So even if Charles is busy with Appel, that's going to leave Pedersen with a lot of openings. Pedersen has the opportunity to have a big game for the Cardinal. -- Beth Mowins

How will Connecticut freshman Tiffany Hayes perform on the big stage? If Renee Montgomery or Maya Moore get into foul trouble, it could be a long night for Connecticut. -- Rebecca Lobo


UConn's Maya Moore. If, somehow, all else is failing for UConn on the offensive end, coach Geno Auriemma always has the option of running a play for Moore. No one delivers in those situations quite like the super sophomore. Look no further than last year's Final Four meeting between the Huskies and Cardinal to see how important having one player to save a bad possession, consistently finish in transition or create a scoring opportunity at the end of the shot clock can be. Candice Wiggins' ability to do that a year ago was a key to Stanford's upset. When she gets just a little selfish, Moore is brilliant in those circumstances, rarely taking a bad shot or forcing a pass. Stanford no longer has that player. And Moore is the one Husky who won't have a completely off night. She will find a way even if the stroke isn't there. -- Charlie Creme