What are the keys to Sweet 16 victories?

What are the X factors in the regional semifinals? How can Cal chip away at Connecticut's armor? ESPN.com columnists Graham Hays and Mechelle Voepel know which key factors could determine who moves on to the Elite Eight. (And click here to see which teams they picked to win.)

Trenton Regional

No. 4 California vs. No. 1 Connecticut (ESPN, noon ET Sunday)

Even if it's like the soft spot on a diamond-encrusted steel bar, Connecticut's softest spot might be post depth. Although the Huskies are a tremendous rebounding team across the board, strictly in terms of size and matching up on the defensive end, there isn't much there beyond Tina Charles and 15 to 20 minutes of Kaili McLaren.

So this could be competitive if: 1. The Bears can get the ball inside to Ashley Walker and Devanei Hampton (who has averaged 14.7 points and 9.7 rebounds in her past three games). 2. The perimeter players can shoot more like they did in the regular season than in going 16-of-73 from behind the arc in the Pac-10 tournament and first two rounds of the NCAA tournament.
And 3. The tournament's top seed compounds things with a bad shooting night.

But as Rube Goldberg experiments taught us all in middle school, the more steps that are required to achieve a single goal, the more likely it is something breaks. -- Graham Hays

No. 6 Arizona State vs. No. 2 Texas A&M (ESPN2, 2:30 p.m. ET Sunday)

An otherwise infrequent traveler east of the Mississippi River, Arizona State has gone 2-2 on the (metaphorical) shores of the Atlantic in the past two NCAA tournaments, losing to Rutgers in Greensboro in 2007 and Duke in College Park in 2008. On both occasions, the Sun Devils were beaten badly on the boards. But that's not the only area in which this year's team is statistically better than past editions; it's an area in which the loss of leading scorer Dymond Simon isn't crippling. The same goes for taking care of the basketball, where Arizona State ranked No. 22 in the nation in assist-to-turnover ratio.

Between them, Arizona State veteran Briann January and Danielle Orsillo have a 1.88 assist-to-turnover ratio. And as good as what Texas A&M saw in the Big 12 this season, that's still even better than Oklahoma's Danielle Robinson and Whitney Hand (1.25), Baylor's Kelli Griffin and Jhasmin Player (1.22), Iowa State's Alison Lacey and Heather Ezell (1.72) and even Kansas State's Shalee Lehning and Kari Kincaid (1.87).

If the guards don't wilt under the heat applied by Texas A&M, Sybil Dosty, Lauren Lacey and Kayli Murphy could then do some damage around the basket on the resulting possessions, either off first looks or second chances.

On the flip side, with Simon out of the mix, Arizona State might struggle to keep Danielle Gant, Takia Starks and Tanisha Smith penned in, especially if young point guards Sydney Colson and Sydney Carter aren't fazed by the pressure the Sun Devils apply.

And the Aggies might not get many points out of their posts or dominate the glass, but for a team known for its defensive tenacity, the players get their points. Since losing at Texas Tech on Feb. 11, Texas A&M has been shooting 44.7 percent from the floor, compared to 42.5 percent before, and turning over the ball just 12 times a game, compared to 16.5 times a game before. -- Graham Hays

Oklahoma City Regional

No. 7 Rutgers vs. No. 6 Purdue (ESPN2, 7:30 p.m. ET Sunday)

It just might come down to which guard named Brittany contributes more: Rutgers junior Brittany Ray or Purdue freshman Brittany Rayburn. That's because it could be someone besides one of the established stars who makes the biggest difference in what should be a meeting of pretty evenly matched teams. Ray had 12 points and five rebounds in the rout over Auburn, while Rayburn came off the bench to play 25 minutes and score 18 points against North Carolina.

Either Ray or Rayburn -- or both -- could take some pressure of their teams' respective leading scorers, Epiphanny Prince and Lindsay Wisdom-Hylton. Ray averages 10 points per game and leads the Scarlet Knights with 47 3-pointers. Rayburn, who averages 9.8 ppg, has hit 43 3-pointers, second-best for Purdue behind Jodi Howell's 56. -- Mechelle Voepel

No. 4 Pittsburgh vs. No. 1 Oklahoma (ESPN2, 10 p.m. ET Sunday)

The Sooners' young guards, sophomore Danielle Robinson and freshman Whitney Hand, can make Courtney and Ashley Paris' job easier with how well they control the pace of the game and defend the Panthers on the perimeter. Robinson and Hand have support off the bench, too. Robinson's length and quickness are part of what make her such a good defender, although trying to limit Shavonte Zellous will no doubt be a team effort. Hand has been getting her shooting touch/range back after her time off following a fractured left index finger. She didn't hit a shot in the Big 12 tournament, then was 2-of-13 in the NCAA tournament's first round. But she was 5-of-9 in the second round.

If OU's guards play well, it's a near-certain thing the posts will hold up their end of the bargain. OU has been to the Final Four before (2002), but neither this group of Sooners nor anyone on the Pitt team has gotten further than the Sweet 16. -- Mechelle Voepel