WNBA playoff X factors, predictions

We know who "won" the WNBA regular season: the Phoenix Mercury. Their 29-5 finish set a league record for most victories in a season and sends them into the playoffs as the obvious favorite.

Before the postseason begins Thursday (ESPN2 and WatchESPN, 7 p.m. ET), we take a look at the conference semifinals. Who's hot and who's not of the eight teams still playing? Might there be an upset or two brewing? Here's a series-by-series breakdown:

No. 1 Phoenix (29-5) vs. No. 4 Los Angeles (16-18)

The Sparks have been consistently inconsistent. Every time you thought they'd turned a corner, it turned out they were just turning in circles. Firing coach Carol Ross in July didn't fix that. By contrast, Phoenix has been consistently great virtually all season. Hard to see either of these things changing dramatically in this series.

Key matchup: Candace vs. Candice. Candace Parker didn't play in two of the Sparks' five losses this season to the Mercury. But she had two of her better games of 2014 in the two closest losses, which were both by five points. In those two contests, Parker combined for 50 points and 19 rebounds. She's averaging 19.4 PPG overall.

Meanwhile, Candice Dupree is having another terrific season in what has turned out to be a very good career. Dupree is averaging 14.5 points and 7.6 rebounds. As great as Diana Taurasi and Brittney Griner have been for the Mercury, Phoenix wouldn't be this strong without Dupree.

X factor: Kristi Toliver. Will Los Angeles have the sharpshooter version of Toliver, who can be extremely effective in opening things up for the interior players? Or the bricklayer version, who can shoot the Sparks out of games?

Regular-season series: Mercury went 5-0.

Mechelle Voepel's prediction: Mercury in two games. Phoenix beat Los Angeles last year in the playoffs when that was more of an upset. This year, it would be a huge stunner for the underdog Sparks to return the favor. The Mercury lost just once at home this season, while the Sparks were 7-10 in Los Angeles.

Michelle Smith's prediction: Mercury in two games. Phoenix is too good and the Sparks too inconsistent to make this as competitive a series as it should be. Candace Parker hasn't been at full strength, and Los Angeles hasn't been able to win consistently at home.

No. 2 Minnesota (25-9) vs. No. 3 San Antonio (16-18)

The Lynx won the first four meetings this season. Then the Stars caught the defending champions at the end of their three-game slide in the last week of the regular season. Was that evidence of Minnesota having some vulnerability? Or just the Lynx easing up in games that really did not mean much to them, as they had second place in the West secured? This playoff series should give us that answer.

Key matchup: In the paint. Minnesota's Maya Moore (league-best 23.9 PPG) will do her damage from inside and out. Both teams' backcourts are really good, and sometimes spectacular. But who will emerge on the interior as the most effective, especially on the boards: Minnesota's Janel McCarville/Rebekkah Brunson or San Antonio's Jayne Appel/Sophia Young-Malcolm/Danielle Adams?

X factor: Jia Perkins. There will be a lot of emotion for San Antonio, which is playing to extend Becky Hammon's career. But it's another guard, Perkins, whose offense might be critical for the Stars to have a chance to upset the Lynx. Perkins, who missed 11 games to injury this season, appears back strong. She had 23 points against the Lynx in the Stars' Aug. 15 victory.

Regular-season series: The Lynx went 4-1.

Voepel's prediction: Lynx in two games. Yes, the Stars really want to at least go the distance in this series for Hammon, who will retire from playing when this season ends. But Minnesota will not be feeling sentimental; the Lynx want to repeat their championship and win their third title overall.

Smith's prediction: Lynx in three games. If Friday night's Stars win was any indication, this could be a great series. But Minnesota knows how to do this, and with home-court advantage will come out the winner.

No. 1 Atlanta (19-15) vs. No. 4 Chicago (15-19)

Nothing has come easily this season for Chicago, which has been seriously challenged by injuries and illness. When healthy, the Sky are much like last year's squad that finished with the best record in the East. But they had to hobble through most of June and July without Elena Delle Donne, who battled a recurrence of Lyme disease. Since she came back July 31, the Sky have been able to get five crucial wins to gain their playoff spot. The return of guard Courtney Vandersloot this month helped, too.

Meanwhile, Atlanta hasn't been as consistent a team as the Dream hoped they would be, despite another MVP-caliber season from Angel McCoughtry (18.5 PPG). But they had their challenges, too, including new coach Michael Cooper's brief time away from the team to be treated for tongue cancer. The Dream were the only Eastern Conference team to finish with a winning record, but they've had two stretches this season where they've lost at least four consecutive games.

Key matchup: The benches. How big an impact will All-Star Game MVP Shoni Schimmel make as a reserve for Atlanta? She definitely has had her moments, including a recent 24-point performance against Phoenix on Aug. 13. Meanwhile, Allie Quigley has led the way off the bench for Chicago, and she has been a dependable scorer when the Sky has really needed that.

X factor: Sylvia Fowles. Big Syl missed 14 games and didn't start her season until June 25. With Sancho Lyttle and Erika de Souza on the other side, the Sky need Fowles to be closer to her old self in this series.

Regular-season series: The Sky had the edge, 3-2.

Voepel's prediction: Sky in three games. Yes, that would be an upset. But the Dream's 2-6 record in August is cause for concern that Atlanta just isn't in sync going into the postseason. Then again, we've said that before with the Dream, even in years they made the WNBA Finals.

Smith's prediction: Sky in three games. With Delle Donne back, the Sky are starting to look like the team that started the season so strong. And the Dream look like a team on the wane, even with home-court advantage. Upset happens here.

No. 2 Indiana (16-18) vs. No. 3 Washington (16-18)

The Fever are in the playoffs for the 10th consecutive year, which is a testament to the overall strength of the organization, its coaching and its superstar, Tamika Catchings. This year -- Catch's 13th season in the WNBA -- back issues kept her out until July 5. That didn't stop her from scoring the winning basket in the All-Star Game or leading the Fever in scoring again (16.1 PPG).

Meanwhile, Washington made some big changes in coach Mike Thibault's second season in D.C., including the trade of Crystal Langhorne. It took a lot of this season for the Mystics -- who are pretty young overall -- to really figure out who they were. But they've seemed to get it, especially in the last month of the regular season.

Key matchup: Coaching. This is Lin Dunn's last year on the sideline for Indiana, and she has had to bring this team along -- both with nurturing and some tail-kicking. Dunn's Fever beat Thibault two years ago in the Eastern Conference finals when he was still coach of the Connecticut Sun. These are two coaches who've strategized against each other for a long time, and they're two of the best at that that you'll find.

X factor: Erlana Larkins. The Indiana forward has to rebound, which is one of the things she does best. If the Fever can get double-digit scoring from her as well, all the better. But defense and working the boards are what the Fever need from her most.

Regular-season series: They tied 2-2.

Voepel's predictions: Fever in three games. As befits a series that was split between the teams this season, we can expect this to go the distance.

Smith's predictions: Fever in three games. Dunn's final season is going to end with a first-round playoff win over a Washington team that came into the postseason with three losses in four games.