(C. Morgan Engel/NCAA Photos via Getty Images)

The NCAA Division I softball tournament starts Friday, with all 64 teams aiming to advance to the Women’s College World Series.

No. 1 Oklahoma once again headlines one of the 16 regionals as the Sooners look to defend last year’s title.

But No. 2 Florida State, No. 3 Virginia Tech, No. 4 Arkansas and No. 5 UCLA will make their case as title contenders. UCLA has won the most NCAA softball titles of any program and once again fields a strong team, while Florida State will be looking to avenge its loss in last year’s final series.

Can anyone stop Oklahoma?

Entering regionals, Oklahoma owns the top spot in the NCAA in team batting average (.367), runs per game (9.26) and ERA (0.81). The Sooners have lost just two games and have won 35 of their 49 games via run rule.

Only two teams have beaten Oklahoma this season, and both are in the tournament. Texas knocked off the Sooners during the regular season, ending their 40-game winning streak. Oklahoma State, meanwhile, got their Bedlam revenge in the Big 12 tournament to win their first-ever conference tournament title.

But aside from the two stumbles, Oklahoma has been largely unbeatable all season long. It’s a similar tune to last year, when the Sooners beat Florida State in three games to win the national title.

Jocelyn Alo has continued to be a formidable force at the plate, breaking the NCAA record for most career home runs across baseball or softball. In the circle, Hope Trautwein (.31), Jordyn Bahl (.95) and Nicole May (1.11) all rank in the top 10 for ERA, creating a triple threat that teams have had a hard time going up against.

While the Sooners certainly aren’t infallible, they are the hardest draw in the tournament when both sides of the ball are clicking. They’ve been in this position before and have always known how to respond. The question is, will their opponents?

Which one of the newcomers will make a splash?

Of the 64 teams featured in this year’s tournament, four are making their appearance for the first time: Grand Canyon University, North Texas, Murray State and UNC Wilmington.

Murray State holds the best team ERA of the grouping, standing at 1.47 and good for third in the country. The Racers won the Ohio Valley Conference tournament title for the first time last weekend, won their first regular-season championship and amassed 40 wins on the season.

But they’ll be going up against Stanford in the first round — and they could be rattled after being involved in a bus crash Wednesday en route to their regional site. Three members of the team were hospitalized non-life-threatening injuries, and the rest of the team was unharmed, but they’ll face a quick turnaround for Friday’s game.

Grand Canyon, in its first year under Shannon Hays, has had quite a season, winning its first Western Athletic Conference Tournament championship.

With three transfers that boast College World Series pedigrees (DeNae Chatman, ASU; Kinsey Koeltzow, Oklahoma; Macee Barnes, Oklahoma State), the team has made its first-ever NCAA tournament regional appearance.

The Lopes will go up against UCLA, a tough test in the first round, but they boast a potential game changer in Gianna Nicoletti, who is one of the nation’s top base stealers.