What does Billy Seidl do when baseball stops calling? He doesn’t hang around the edges of the game. Instead, he finishes his degree, enrolls in a finance program and plans a wedding.
Most people met him through someone else. Brielle Biermann’s Instagram post in 2024 turned the pitcher into a search term. But the full story starts in Massachusetts. Then it runs through a championship at Duke and three seasons in the White Sox system.
Billy Seidl in Brief
Billy Seidl is a former White Sox minor-league pitcher, born November 9, 1999, in Newton, Massachusetts. He grew up in the Boston suburbs and starred at St. Sebastian’s School before pitching at Duke. Chicago drafted him in the 15th round in 2022. Winston-Salem released him on March 20, 2025. Since then, he’s earned his Duke degree and moved toward finance. He’s also planning his wedding to Brielle Biermann.
What Billy Seidl Has Said About His Path, Year by Year
Billy Seidl doesn’t give many interviews. The on-record material is thin: one postgame answer in 2021, a few Instagram captions and a short cameo in a fan Q&A.
So this profile leans on his own words where they exist. Beyond that, it uses named coaches, official records and Bravo’s reporting. Where he stays quiet, we say so.
Early Life: A Baseball Family in Massachusetts
William Randall Seidl was born in Newton, Massachusetts. His parents are Randall and Janet Seidl. He has two brothers, Tommy and Philip, and a sister, Shannon, per Duke Athletics.
Baseball ran through the family. His older brother Tommy played at Harvard, then at Alabama in 2022 and 2023, according to MiLB.
Billy finished at St. Sebastian’s School in Needham, an all-boys Catholic school, in 2019. There he played two sports. He lettered four years in football as a quarterback. At the same time, he became one of the state’s top pitching prospects.
His junior spring set the tone. He went 7–0 across seven appearances, per Duke Athletics, with a 0.58 ERA over 48⅓ innings and 63 strikeouts. The Independent School League named him both its MVP and its Most Valuable Pitcher.
Perfect Game ranked him the second-best right-hander in Massachusetts. It also listed him as a top-500 national prospect. Then it named him to its 2018 Underclass All-American Third Team.
Duke coach Chris Pollard announced the signing in February 2019. He called Seidl “a true power arm.” He said the right-hander sat at 92 to 93 miles per hour with a slider that finished hitters. Pollard even floated a future as a closer.
Duke: A Lost Season, Then a Title Run
Seidl enrolled at Duke in 2019. But he didn’t pitch in 2020 because of the pandemic, per MiLB. So his college career really began in 2021.
That April, he made his first career start against N.C. Central. He threw two scoreless innings and struck out four of the six batters he faced, per Duke Athletics.
Then came May. Duke entered the ACC tournament as the ninth seed. Pollard handed the opener against Florida State to the largely unproven sophomore, according to the Duke Chronicle.
Seidl went 3⅓ innings, allowed one run and struck out six in a 12–1 win. He’d had starts before, so the assignment wasn’t a shock, he said. Still, he knew the setting mattered. “It’s the ACC tournament,” he told the Chronicle.
Four days later, Duke beat N.C. State 1–0 for its first ACC tournament title. The Associated Press called it the program’s first ACC championship since 1961. Duke Athletics adds that its staff posted a 1.00 ERA across the event.
His 2022 junior year started with a flash. In his season debut, he threw four hitless innings with six strikeouts. By March 10, Duke’s own game notes had him leading the nation in hits allowed per nine innings at 1.32. Pollard called one March start “electric.”
But the numbers slid. By draft day, Seidl stood at 2–5 with a 6.80 ERA over 43⅔ innings. He’d made 17 appearances, nine of them starts. MiLB lists his two-year Duke line at 6–5, with a 6.55 ERA and 89 strikeouts in 68⅔ innings.
Chicago still bet on the arm. Teammates Graham Pauley and Jimmy Loper joined him in that draft class.
The White Sox Years
Chicago took Seidl in the 15th round, No. 461 overall, in July 2022. He signed on July 25 for $100,000, per MiLB.
That bonus is the best-documented number in his financial record. Our [INTERNAL LINK: Billy Seidl net worth → Billy Seidl net worth article] breakdown puts his estimated total at $100,000 to $250,000. No verified disclosure exists.
He reported to the Arizona Complex League White Sox on August 11, 2022. After three games there, he moved up to Class A Kannapolis on August 24, per MLB.com transaction records. Across eight games that season, South Side Sox lists him at 2–0 with a 1.00 ERA and one save.
That blog ranked him No. 103 on its 2023 White Sox prospect list. It said his first taste of pro ball flashed “something much more than a 15th-rounder.” Then he spent all of 2023 at Kannapolis, per MiLB.
In 2024, Seidl opened the year in the White Sox system again. On June 13, Chicago moved him up to High-A Winston-Salem, per MLB.com. The jump was rough. His ERA there sat at 5.92 by early September.
After that, the Dash released him on March 20, 2025. FanGraphs now lists him as a free agent. We found no report of a new contract.
His career totals across the system come to 10–7 with a 4.39 ERA. He struck out 113 batters in 110⅔ innings.
After Baseball: Degrees and Spreadsheets
While he pitched, Seidl also worked remotely. His LinkedIn profile lists a B2B sales role from October 2023 to July 2025. It also lists an investment analyst job at Lion’s Park Capital, starting in May 2025.
Meanwhile, he finished at Duke. He graduated in June 2025 with a Bachelor of Arts in Sociology, Markets, and Management Studies, per published profiles. We found no report that he joined an independent club.
That August, he enrolled at UVA’s McIntire School of Commerce on the finance track. The school runs that master’s as a 10-month program. Directory listings suggest he’s since moved into analyst work. But we couldn’t confirm an employer from a primary source, so we’re not naming one.
Billy Seidl and Brielle Biermann
Billy Seidl met Brielle Biermann in the Bahamas in 2023, per Bravo. The two kept it quiet at first. In April 2023, he posted their first photo together, captioned “Whole lotta Rizz,” per HollywoodLife.
Brielle later explained the privacy. Her parents’ divorce was playing out, and she was tired of criticism. “I didn’t want anyone to affect what we had going on,” she said, per Bravo.
Billy proposed in Scottsdale, Arizona, on February 26, 2024, per Bravo. That was the day after her 27th birthday. People reported that he asked her adoptive father, Kroy Biermann, for his blessing first.
No family attended. Brielle said she wanted the moment to be just the two of them and photographer Ty French. She announced it with the caption “Forever with you,” per ET Online.
The ring in those photos isn’t the one she wears. Brielle explained that they were flying out that night. So Billy asked her sister Ariana to bring the real ring the next day.
Now the wedding is coming. Brielle has said it will be at a venue in Naples, Florida, where Billy’s parents live, per Bravo. In October 2025, she posted that she’d finally locked in a venue and date.
In July 2026, she told TMZ the wedding was “soon” and would be on the beach, per AOL. She didn’t give a date. Some outlets have cited unnamed sources pointing to November. We’re not treating that as confirmed.
What This Means to Them, In Their Own Words
Seidl’s public words are short and plain. In 2021, he talked about the setting, not himself. In 2023, he captioned a photo of Brielle in three words.
Brielle speaks for the couple far more often. She’s said she wanted a long engagement to enjoy each stage. She’s also said she was first drawn to his chivalry and kindness, per Bravo.
That’s the whole on-record picture, and it’s thin. We found no interview from Seidl since his release. The silence is part of the story.
What Reporters Found That Wasn’t in the Interview
Reporting and records differ in a few places. None of the differences point to anyone being careless or untruthful. They’re just worth knowing.
- Hometown: MLB lists Newton as his birthplace. Duke lists Wellesley as his hometown. His school is in Needham.
- Starter or swingman: MiLB describes his Duke line “as a starter.” South Side Sox counts 33 games and 13 starts over two years.
- Coach’s forecast: Pollard saw a possible closer in 2019. Chicago listed him as a relief pitcher.
- Proposal date: Bravo dates the proposal to February 26. Coverage of her announcement varies by a day.
- Net worth: Public estimates vary by a factor of ten or more. None cite a primary source.
Final Take on Billy Seidl
Billy Seidl’s story isn’t about a record or a fortune. It’s about a pitcher who planned past the game. A 7–0 junior year, an ACC title and a $100,000 bonus got him started. A release in 2025 didn’t stop him.
Now he’s 26, holds a Duke degree and is studying finance. He turns 27 on November 9, 2026.
More on This Topic: Billy Seidl Net Worth: What a Minor League Pitcher Actually Earned
Billy Seidl FAQs
How old is Billy Seidl?
He’s 26. Billy Seidl was born on November 9, 1999, and turns 27 on November 9, 2026.
Where did Billy Seidl go to college?
He attended Duke University and graduated in June 2025. That August, he enrolled at UVA’s McIntire School of Commerce.
Is Billy Seidl still playing baseball?
No. The Winston-Salem Dash released him on March 20, 2025. FanGraphs lists him as a free agent, and we found no new contract.
Who is Billy Seidl’s fiancée?
She’s Brielle Biermann, a former Don’t Be Tardy cast member. [INTERNAL LINK: Brielle Biermann → Brielle Biermann biography]
How much did Billy Seidl sign for?
He signed with the White Sox on July 25, 2022, for $100,000. Our estimate of his net worth is $100,000 to $250,000, with no verified disclosure.
When is Billy Seidl’s wedding?
No exact date is public. Brielle has said the venue is in Naples, Florida, and that the date is set.
Disclaimer: Every detail in this profile is compiled from publicly available reporting, league records, and official team announcements. Nothing here should be read as a confirmed statement from Billy Seidl, Brielle Biermann, or their representatives.
Sources: Duke Athletics roster page · MiLB player page · Bravo, “Brielle Biermann Answers Burning Questions About Her Engagement”
Also cited in-text: MLB.com transaction records, Duke Chronicle, South Side Sox, The Associated Press, ET Online, People, AOL, FanGraphs, UVA McIntire School of Commerce, LinkedIn.
