Ethan Crelinsten's path to professional grappling defies the typical narrative. Born on May 14, 1994, in Canada, he had little exposure to competitive athletics in his early years. His first contact with organized sport came at 19, when the surging popularity of cage fighting in Canada pulled him toward mixed martial arts. The sport was experiencing a cultural moment, and Crelinsten, like many young Canadians of his generation, was drawn into the enthusiasm surrounding it.

His earliest training took place at a small local gym with a curriculum built around striking and wrestling — jiu-jitsu was nowhere in the picture. The turning point came when he moved to TriStar Gym in Montreal, one of Canada's most respected combat sports facilities. Under the instruction of Firas Zahabi, he encountered jiu-jitsu for the first time. What began as a supplementary discipline gradually consumed him entirely. Crelinsten discovered that jiu-jitsu resonated with him in a way MMA never had, and he made the deliberate decision to abandon the broader sport in favor of submission grappling exclusively.

The chain of events that brought Crelinsten into the orbit of John Danaher began at TriStar through an unlikely intermediary. TriStar fighter Tom Breese arranged for Gordon Ryan — one of Danaher's most decorated students — to visit the Montreal gym for a fight camp. Ryan's technical level left a profound impression on Crelinsten. He recognized immediately that what he was witnessing reflected a caliber of jiu-jitsu instruction unavailable to him locally, and that realization sent him directly to the source: the Renzo Gracie Academy in New York, where Danaher ran his now-legendary training group.

Crelinsten's development under Danaher was rapid, and his competitive results confirmed it. He eventually earned full membership in the Danaher Death Squad, the elite grappling unit that dominated the no-gi scene throughout the late 2010s. His belt progression, however, remained anchored to Firas Zahabi, who awarded every rank from white through brown belt in a co-tutoring arrangement with Danaher. The black belt arrived in November 2020, presented by Danaher himself on the same day Nicky Ryan received the same promotion — a formal recognition of what competition had already made plain.

The scope of Crelinsten's impact was such that he earned a profile on BJJ Heroes before receiving his black belt — reportedly the first athlete to achieve that distinction on the platform, a testament to how thoroughly his results had outpaced his rank.

Few stories in modern no-gi grappling command attention quite like Crelinsten's run through the ADCC Trials circuit as a colored belt. In 2017, he claimed first place at the ADCC West Coast Trials. In 2018, he followed with a victory at the ADCC East Coast Trials — both results achieved without a black belt. Along the way, he defeated established professionals with far greater experience on paper, making his wins all the more striking to the no-gi community.

Those Trials victories did more than add hardware to a résumé; they announced Crelinsten as one of the most technically complete sub-only competitors in North America, regardless of rank or age. The combination of Danaher's systematic instruction and Crelinsten's rapid assimilation of leg lock and positional concepts made him a genuinely difficult puzzle for opponents at every level. He returned to the ADCC East Coast Trials in 2023, placing third — a result that demonstrated continued elite-level engagement with the format well into his career.

In July 2021, John Danaher announced the dissolution of the Danaher Death Squad as a unified training and competition team. In a public statement, Danaher cited disagreements over facility location, personality conflicts, clashing values, and a growing tension between the collective team brand and the increasingly prominent individual brands of its members. For a group that had reshaped the landscape of no-gi grappling, the announcement closed a defining chapter.

Crelinsten moved quickly alongside Craig Jones and Nicky Rodriguez to establish what would come next. During the summer of 2021, the three announced the formation of the B-Team, headquartered in Austin, Texas. The project was built on a shared competitive philosophy and a commitment to operating independently of larger institutional structures. Within a short time, B-Team established itself as one of the most recognized and respected independent grappling squads on the no-gi circuit, drawing athletes and producing results that validated the model its founders had envisioned.

On March 7, 2026, Crelinsten headlined Polaris 36 in Croydon, England, in an event broadcast exclusively on FloGrappling. Facing Shaï Gerena in the main event, he secured a submission finish in the first round, adding another significant result to an already extensive competitive record. The victory reaffirmed his standing as one of the premier no-gi competitors on the Polaris platform, and his post-fight comments suggested he had held a championship belt for a considerable stretch of time leading into the event.

What followed the finish generated attention well beyond the grappling community. Immediately after the win, Crelinsten issued a direct public callout aimed at UFC BJJ, declaring his intention to compete for that organization's belt and to participate in the Octobowl: "I had this (Polaris) belt for a while, and UFC BJJ, I want that f—ng belt! I want that Octobowl, I want to be in there. UFC BJJ hit me up, I'm coming for that belt!" The callout carried additional weight given the well-documented competitive tension between FloGrappling and the UFC as rival forces in the grappling broadcast landscape — making Crelinsten's public pivot toward a UFC BJJ platform all the more pointed. The moment was further contextualized by the fact that his B-Team teammate Nick Rodriguez had signed with UFC BJJ around the same period, signaling a broader organizational shift within the B-Team camp toward that emerging competitive outlet.

Crelinsten's career has been defined almost entirely by no-gi and submission-only formats — the environments in which the Danaher system is designed to thrive. Across appearances at the ADCC World Championships, Polaris, Kasai Pro, and a range of invitational events, he operates as a submission hunter rather than a points accumulator. That philosophy is reflected in titles such as Finishers Sub-Only Champion and Sapateiro Invitational Champion. The 2020 competitive season illustrated the depth of his skill set with particular clarity: he won the Jitz King Invitational outright while finishing as runner-up at both the BJJ Fanatics 170lbs Grand Prix and the P-Belum Invitational.

Crelinsten competes in the Peso Pena division, roughly 154.5 lbs (70 kg), a weight class in which his combination of leg lock fluency and upper body submission awareness makes him a persistent threat. As of late 2024, he had begun exploring mixed martial arts training with B-Team teammate Damien Anderson — a sign that the competitive curiosity first sparked at age 19 had not entirely faded, even as his grappling career continued producing results at the sport's highest levels.