COLUMBUS, OH — Hendrik Vos, 38, a third-degree black belt and two-time no-gi world champion, has been on continuous seminar tour since January 2024 and currently cannot identify a single one of his host instructors without consulting the calendar app on his phone, sources at his Saturday stop confirmed.
This month alone, Vos has visited 47 academies across 14 states at $175 per head, netting roughly $88,000 in teaching fees before the host gyms’ cut, despite being unable to verify whether the man currently shaking his hand and calling him “brother” runs a school in Sacramento, Akron, or Fort Wayne.
“He asked me how my flight was,” said Marcus Hallows, owner of Iron Bridge Jiu-Jitsu in Columbus. “I drove him here. I picked him up at a Sheetz off I-71 because he said the airport was too far. He hasn’t been on a plane in nine days. He drove from Cleveland.”
Vos, asked Saturday at Iron Bridge whether he remembered teaching there in November of last year, confidently said yes. The academy’s records confirm Vos has never visited before. Records further confirm Vos has now taught at fourteen different gyms named “Iron” in the last eighteen months, and that he has, in chronological order, conflated Iron Will Grappling (Tampa), Iron Crown BJJ (Pittsburgh), Iron Phoenix (Albuquerque), Iron Bridge (Columbus), Iron Forge MMA (Sioux Falls), Iron Apex (Bakersfield), Iron Ridge Combat (Worcester), and Iron Cross Jiu-Jitsu (Springfield, MO) in interviews, social media tags, and a thank-you reel posted last Wednesday in which he addresses the camera and says, “Thanks to everyone at Iron… uh… thanks to everyone.”
The seminar package — always identical — consists of three leg entanglements (the inside sankaku, the outside ashi, and what Vos calls “the new one” but which his peers describe as “an old one”), one guard retention detail, and a 15-minute Q&A during which Vos tells the story about the ADCC semifinal he lost to his own teammate. He has told this story 47 times this month. He has told it four times at the same academy.
“He told it Friday,” said Mike Hallows, head instructor at Peak Grappling in Fort Wayne. “He told it last March. He told it the previous October. He told it the year before that. Every time, he says, ‘something you guys probably haven’t heard before.’ I have heard it before. I introduced him.”
Hallows, no relation to the Marcus Hallows in Columbus, has also been called Mark, Mike, Mick, Matt, and at one point “buddy with the beard” by Vos within the same seminar weekend.
A sample of 12 host academies surveyed for this article reports that Vos has, this calendar year, asked for a ride from the airport 100% of the time, returned the favor of remembering any single host student’s name 0% of the time, used the phrase “what’s up, killer” when greeting a student whose actual name was on a laminated badge clipped to their gi 73% of the time, and signed an instructional DVD case that the host instructor was just trying to politely hand back to him 41% of the time. A separate question — whether Vos correctly identified the city he was currently in within the first six hours of arrival — returned a single yes (Tampa, where the airport sign is unusually large).
Hosts further report that Vos’s standard reply to “how was your flight?” is “it was fine,” delivered with a small head nod, regardless of whether he actually flew. On at least three documented occasions this quarter, Vos arrived at a host academy via a 14-hour drive in his own vehicle and, when greeted with the standard hospitality question, said “it was fine” before launching into a five-minute story about TSA.
His scheduling agent — a Squarespace form he has never opened, which forwards inquiries to a Gmail address he set up in 2017 and has not signed into since — has booked him for the rest of 2027. Deposits are non-refundable. A summary of confirmed bookings reviewed for this article includes at least nine simultaneous obligations during the third week of June, six of which are at gyms also named “Iron,” all of which list Vos’s headshot prominently on flyers Vos has not seen.
Asked by this publication whether he could name the host instructor at his next stop, Vos paused, opened his calendar app, scrolled, said “Justin,” and got on a stationary bike. The next host instructor’s name is Devin.
His second-degree black belt student, Caio Andradina, who is now booked to substitute for Vos at four upcoming seminars where Vos has accidentally double-booked himself, said the situation has reached a stable equilibrium.
“He doesn’t know where he is, the gyms don’t know who else is teaching there that weekend, and the students keep paying,” said Andradina. “Everybody’s kind of okay with it. The leg lock works.”
A separate sub-survey of host instructors found that Vos has, in the last calendar year, mailed a “thank you for the great weekend” handwritten card to thirty-four academies. Seven of those academies he has never visited. Two of them do not exist; their addresses correspond to a Best Western in Pensacola and an empty lot in Norman, Oklahoma.
At press time, Vos had finished his Q&A at Iron Bridge, asked the host whether anyone could give him a ride to “the airport or the train station, whichever,” and signed a copy of Mike Hallows’s Peak Grappling t-shirt for someone he believed to be the gym owner.
The host instructor was three feet to his left.