COLUMBUS, Ohio – Ohio State head softball coach Kirin Kumar has finalized her staff. Courtney Vierstra, Caitlyn Nolan and Matthew Guemmer have come aboard as assistant coaches. Each new member of the staff previously worked with Kumar at prior coaching stops – Vierstra and Nolan at Miami University and Guemmer at Virginia Tech.
All three coaches have made numerous postseason appearances and been of staffs that were named NFCA Regional Coaching Staffs of the Year.
"I'm excited to hire a staff that are both amazing coaches and people," said Kumar. "Having worked with them before, I have a great belief in their ability to both recruit top-level student-athletes and connect with our current players. Our values align and I'm honored to work alongside them as we start to chase our goals at Ohio State."
Courtney Vierstra
Vierstra, who will serve as Ohio State's pitching coach, spent the past two seasons on Kumar's staff at Miami University following her standout playing career for the RedHawks. In that time, she helped produce a MAC Pitcher of the Year, a MAC Freshman Pitcher of the Year and two First-Team All-MAC pitchers.
In 2024, as Miami enjoyed its most successful season in program history, Vierstra helped Addy Jarvis register a 19-2 record – the best winning percentage in single-season school history – and Madilyn Reeves earn MAC Freshman Pitcher of the Year accolades while going 22-4.
In her first season on the Miami staff, Vierstra mentored Bri Pratt, who after a 32-12 campaign was named the MAC Pitcher of the Year. Pratt posted career bests in wins (32), games started (44), complete games (34), innings pitched (270.1) and strikeouts (207).
Vierstra, who completed her playing career in 2022, ranks in the top-five in eight different career pitching records. Highlighted by 84 career wins (second all-time), she also ranks second in win percentage (.667), appearances (166), starts (109) and strikeouts (1,005). She's third in innings pitched (779.2) and shutouts (27) and is fourth with 69 complete games.
A three-time first-team All-MAC honoree (2019, 2021, 2022), Vierstra was named the Mid-American Conference Pitcher of the Year in 2021. She finished the 2021 season with a 26-5 record, throwing three perfect games and four no-hitters that season alone. Miami would go on to finish the 2021 season at 46-10 overall and 36-2 in MAC record, both conference bests.
The Thornville, Ohio, native went 17-9 in 2022, including 13-3 in conference play, helping the RedHawks to both a regular season and MAC Tournament Championship.
Vierstra completed her bachelor's degree in education from Miami and finished her master's degree in educational psychology in 2022 as she wrapped up her playing career.
Caitlyn Nolan
Nolan comes to Ohio State after spending last season with Kumar at Miami University. In 2024, she helped the RedHawks post the best offensive numbers in the nation. Not only did Miami lead the country in runs per game, its 160 total home runs fell one shy of matching the NCAA record for home runs in a season. The RedHawks also led the nation in slugging percentage (.724) and scoring offense (8.7 runs per game) while finishing third in batting average (.348) and fourth in on-base percentage (.451).
Nolan played professionally as a shortstop/second baseman for the Bologna Blue Girls in the Italian A1 Softball League in Bologna, Italy in 2022 and 2023.
Prior to traveling overseas, she served as a student assistant coach for Virginia Tech from 2019-21. Her duties included infield skill and hitting development with the Hokies. During Nolan's three seasons on staff, the Hokies were 105-30 and played in two NCAA Regionals. She also served as an instructor at D-BAT Softball in 2021-22, facilitating infield and hitting instruction for all ages.
Nolan made a name for herself as a shortstop with Virginia Tech from 2015-19. In 201 starts, she recorded a .951 fielding percentage and hit .263 with 27 home runs and 108 RBI. As a senior, she set the single-season record for home runs (19) and was second in school history with 55 RBI. She earned first-team NFCA All-Region honors in 2019.
Nolan graduated from Virginia Tech in 2020 with dual degrees in human development and sociology.
Matthew Guemmer
No stranger to the Big Ten Conference, Guemmer spent the last two seasons as an assistant coach at Rutgers University. While he was there, he helped the Scarlet Knights to new heights in the league, including producing an All-American, All-Big Ten and All-Big Ten Defensive Team outfielder.
After joining the staff, Rutgers placed an outfielder on the Big Ten All-Defensive Team in back-to-back seasons and had defensive outfield plays appear on ESPN's SportsCenter Top 10. Centerfielder/pitcher Morgan Smith became RU's first NFCA All-American with second team honors, was also a First Team All-American by Softball America. She was named the country's top-two way player by Softball America.
In Guemmer's second year at Rutgers in 2024, the Scarlet Knights captured back-to-back 30-win seasons for the first time in program history, the most Big Ten victories since joining the league in 2014-15, the most Big Ten series wins in school history and the highest ever Big Ten Tournament seed.
Guemmer arrived at Rutgers after spending three seasons (2020-2022) at Southeast Missouri coaching the Redhawks outfield defense and hitting while assisting with infield defense and pitching. He helped guide SEMO to back-to-back 30 wins seasons, a 39-16 Ohio Valley Conference record and the 2021 OVC regular-season title.
Prior to his stint at SEMO, Guemmer was a volunteer assistant coach at Virginia Tech and the director of the Peter D'Amour Softball Camps in 2019. It was during this stint at Virginia Tech that Guemmer worked with Ohio State head coach Kirin Kumar. Guemmer and Kumar were part of the 2019 NFCA Mid-Atlantic Region Coaching Staff of the Year; Guemmer was responsible for overseeing the outfielders in a season where the Hokies won their second-ever ACC regular-season title and first-ever Coastal Division crown.
Before joining the collegiate ranks, Guemmer was the head coach of the girls' softball team at De Soto High School in his hometown of De Soto, Missouri. At the helm of the program, he compiled a 76-34 record with three district championships and produced three MHFSCA All-State players and 13 MHSFCA Academic All-State athletes. During his first season after being elevated from assistant coach, he led the Dragons to an MSHSAA 3A state championship and 25-4 record as the team held a .351 batting average and 1.41 ERA and was named the 2014 Regional Radio Dream Team Coach of the Year.
A graduate of the University of Missouri with a degree in secondary education, Guemmer was a student manager with the Tigers softball program for two seasons assisting with camps and clinics, film and equipment.
