NORMAN — The top-seeded Oklahoma softball team (49-2, 18-0 Big 12) begins its quest for a fifth national title this weekend as it hosts an NCAA Regional in Norman beginning Friday. The four-team, three-day event features Notre Dame (36-16, 12-2 ACC) facing Wisconsin (40-12, 12-2 Big Ten) at 6 p.m. CT on Friday on ESPN before the Sooners take on UMBC (30-22, 7-11 America East) at 8:30 p.m. CT Friday on ESPN2.

Friday's winners will square off in the first of three games Saturday, while Friday's losing teams will face off in an elimination game for game two of Saturday's tripleheader. The loser of Saturday's first game will take on the winner of the day's second game in an elimination game later Saturday night. The winner of Saturday's final game will take on the winner of the day's first game on Sunday with an if necessary rematch scheduled for later on Sunday.

The winner of this weekend's regional will advance to the NCAA Super Regional round against the winner of the Evanston regional, hosted by Northwestern, the following weekend with the ultimate goal of reaching the Women's College World Series.

REGIONAL STORYLINES

FAN INFORMATION

Tickets for the NCAA Norman Regional are sold out.

OU Athletics introduced a clear bag policy and walk-through metal detectors at all home events this season. More information can be found here.

POSTSEASON? POSTSEASON.

Oklahoma has made the NCAA Tournament in every year of head coach Patty Gasso 's 25 seasons at the helm of the program and in 26 straight seasons overall. Only Arizona has a longer streak (32 straight), while the Sooners are tied with Washington for second-longest run.

This marks OU's ninth straight year hosting a regional. Overall, Oklahoma is 71-19 (.789) in NCAA Regional play with 17 Regional championships in 25 appearances. In 2018, OU swept the NCAA Norman Regional with three shutouts, outscoring opponents 24-0.

The Sooners are looking to make their 10th straight appearance in the Super Regionals and 13th overall since the format was introduced in 2005. All-time, OU has competed in 12 Women's College World Series and earned four national championships.

THERE'S ONLY ONE OKLAHOMA

For the second time in program history, the Sooners enter the NCAA Softball Tournament as the No. 1 seed. The feat was also accomplished in 2013, when OU went on to earn its second national championship.

In this week's polls, the Sooners remained ranked No. 1 in both the USA Today/NFCA Division I Coaches Poll and the ESPN.com/USA Softball Collegiate Top 25 for the fifth week in a row. Oklahoma is the only program to be ranked every week of the NFCA poll all-time, a run of 366 straight polls.

Speaking of No. 1, Oklahoma leads the nation in the following statistical categories: batting average (.365), earned run average (1.15), fielding percentage (.986), home runs per game (1.90), on-base percentage (.456), shutouts (23), slugging percentage (.675), strikeout-to-walk ratio (6.87) and win-loss percentage (.961).

STREAKING

Oklahoma claimed its eighth consecutive Big 12 regular season title in 2019. With a 18-0 record, OU became the first program to finish Big 12 play undefeated in back-to-back seasons. The Sooners are undefeated in their last 54 conference series (50-0-4 in that span) and have not lost a conference series since 2011.

The Sooners finished the regular season leading the Big 12 in batting average, on-base percentage, slugging percentage, runs scored, hits, triples, home runs, walks drawn, ERA, opponent batting average, shutouts and strikeouts.

OU has finished first in the Big 12 over the past eight seasons with a combined record of 134-13. Prior to OU's current run of eight straight regular-season titles, no team had ever won more than two consecutive titles. Overall, the Sooners have 18 Big 12 titles with 12 regular season crowns and six Big 12 tournament championships, all under current head coach Patty Gasso .

The Big 12 did not name a postseason champion in 2019. The Big 12 Championship was canceled before all pool play games could be finished due to rain and poor field conditions at USA Hall of Fame Stadium. As a result, the regular season champion, Oklahoma, earned the conference's automatic bid to the NCAA Softball Championship.

HOME SWEET 'HOMA

With a 13-0 record at home this season, Oklahoma is currently on a program-record 47-game winning streak. OU's 16-0 victory over Baylor on April 7 marked the 46th consecutive home win, breaking a school record that stood for over 17 years. The Sooners have not lost at Marita Hynes Field since May 20, 2017; the previous program best of 45 straight home wins was achieved from April 14, 2000 to March 29, 2002.

In 2018, the Sooners went 30-0 at Marita Hynes Field, including a 25-0 mark in the regular season. It marked the second perfect home record in school annals, also occurring in 2001 (18-0). Additionally, 30 home wins were the second-most in OU history behind the 2014 team's 32.