[2] In May 2020, she joined and eventually won the inaugural championship in the Athletes Unlimited Softball league as the top individual points leader.

Osterman is so far the second pitcher in NCAA history to strike out 1,000 batters in only two seasons and in that very same game on May 22, during the Women's College World Series vs. the ULL Ragin' Cajuns, she struck out 11 to reach the milestone.

[16] Osterman redshirted from UT to participate with fellow college softball pitcher Jennie Finch in the Olympic Games in Athens.

On July 10, she struck out 13 batters over 5-innings for another no-hitter, this time missing perfection on a lone error by first-baseman Stacey Nuveman in a 16–0 win over the Fort Worth All-Stars.

[24] Beginning on March 4, the Longhorn posted a career best 24.2 consecutive hitless innings when she surrendered a first-inning hit to the Evansville Purple Aces to open a three-game series before shutting them down for the rest of the game.

On March 9, Osterman struck out her 1,200th batter to tie Lisa Ishikawa of Northwestern University for 10th place on the NCAA all-time strikeout list; the victory was also her sixth career perfect game.

[25] On March 11, she moved past Ishikawa and passed Jocelyn Forest of the University of California, Berkeley to take ninth place with a second consecutive no-hitter against the UTEP Miners.

Finally, on March 14, Osterman came on in relief vs. the UCLA Bruins and retired the first five batters before the streak ended with a sixth-inning leadoff single.

Later she would again whiff 24 to match her own school record vs. the Texas Tech Red Raiders and along with Erin Crawford combined for another 31 strikeouts on April 26.

For a fourth time in her career, Osterman led the NCAA in ERA and strikeout ratio, setting a new all-time season record in the latter category at 15.4.

[34] On February 16, she struck out 13 Oklahoma Christian Lady Eagles batters to bring her career total to 1,708, making her just the second pitcher in NCAA history to reach the 1,700 plateau.

[37] On March 1, she struck out 15 batters in a 5–1 win over the UTA Mavericks to bring her career total to 1,807, making her the first pitcher in NCAA Division I history to reach the 1,800 watershed.

[39] On March 17, Osterman struck out 13 Michigan Wolverines batters in her first loss of the season (following 17 consecutive wins) to become the first pitcher in NCAA Division I history to enter the 1,900 Strikeout Club.

On March 18, Osterman recorded her 115th career win over Notre Dame Fighting Irish to pass Andaya and tie Jennifer Stewart and Shelley Laird for 12th place; the next day, she recorded her 116th career win over the Arizona Wildcats to pass the two and tie Kristin Schmidt and Debby Day for 11th place.

On March 22, Osterman recorded her 118th career win—over the Georgia Tech Yellow Jackets—to tie Jamie Southern for 10th place on the NCAA all-time list.

On March 25, she recorded her 119th career win over the Nebraska Cornhuskers to pass Southern and tie Jennie Finch, Brooke Mitchell and Michele Granger for ninth place.

On March 29, Osterman recorded her 120th career win to pass them and tie Britni Sneed and Sarah Dawson for eighth place on the all-time list.

[47] Finally, she owns the ratio record for the NCAA Division I and is top-10 in wins (6th), strikeouts (2nd), shutouts (3rd), WHIP (2nd), perfect games (2nd) and no-hitters (3rd).

[48] On July 2, 2006, Osterman threw a 12–0 no-hitter against the Arizona Heat in the USA Softball Exhibition, missing the perfect game by walking Kaleo Eldridge.

On July 17, 2006, Osterman won the championship game of the 2006 World Cup by beating Team Japan 5-2, giving up two runs on two hits and a walk while striking out 11 batters.

[49] However, even though Osterman had been on their amateur roster for the five seasons prior to being drafted, she chose not to sign with them, making her officially a free agent on September 30.

[50] On May 29, 2007, Osterman pitched her professional debut, striking out 24 batters in a 12-inning, 1–0, win over the Chicago Bandits, which tied the league single game strikeout record.

She won the pitching Triple Crown (only the second pitcher ever to accomplish the feat) and simultaneously set then season records in both the wins and strikeouts categories.

For the streak, Osterman completed 149.0 innings and surrendered 63 hits, 11 earned runs and 40 walks while fanning 237 hitters for a 0.51 ERA and 0.69 WHIP.

On June 12, Osterman picked up the win in Team USA's Gold-Medal 9–0 victory over Australia in the 2005 International Sports Invitational; she gave up one hit and struck out ten batters over five innings.

[68] On May 16, Osterman struck out 14 batters in a complete-game 13–0 no-hit victory over the Visalia All-Stars, missing the perfect game by hitting Lindsey Herrin with a pitch.

[72] The 7-inning no-hitter was just the second in U.S. Olympic history, following Lori Harrigan's 6–0 perfect game against Canada on September 17, 2000,[73] and was Osterman's 100th game-played with the U.S. Women's National Team.

On August 15, following Team USA's 7–0 victory over Japan, Osterman pitched the final 4-innings of the suspended match against Canada, postponed from the previous day due to rain and lightning.

[79] Among her favorite athletes are fellow Texans Roger Clemens and Nolan Ryan, as well as NBA player Hakeem Olajuwon and actor/ director Kevin Costner.

In the bonus features of the "Bad News Bears" DVD, Billy Bob Thornton admits to having a crush on Cat Osterman.