Home / Guides / The ADCC Trials Champion Who Treats

The ADCC Trials Champion Who Treats Instructionals Like Homework, Not TV

Jozef Chen went from a standing start to the youngest ADCC European Trials champion in about five years, and he says the shortcut wasn't more mat time, it was how he studied.

BJJ Gyms · 2026-07-31 · 6 min read

Reviewed by BJJ Gyms · Updated 2026-07-31

Key takeaways

  • Jozef Chen became the youngest ADCC European Trials champion at 19 after roughly five years of training, and he credits his rate of improvement to how he studies, not just how often he trains.
  • His core rule: he won't log a technique from an instructional as something he 'knows' until he has actually tested it live against a resisting partner.
  • He and his coach build constrained positional games that strip away a grappler's favorite tools, forcing them to solve problems they'd otherwise avoid entirely.
  • The approach exposes hidden weaknesses, since free rolling lets skilled competitors mask a gap in one area by leaning on strength somewhere else.
STUDY THE ROLL
Chen's Path By The Numbers
19
Chen's age when he won the ADCC European Trials
~5 yrs
Approximate time from starting BJJ to reaching elite competitive level
1
Live-test rule: a technique only 'counts' once tried against resistance
0
Prior athletic background before he started training in Nanjing

Figures drawn from Jozef Chen's July 2026 interview comments as reported by BJJ Eastern Europe and BJJ Doc.

Five Years From Beginner To Elite

Jozef Chen started training in Nanjing with no real athletic background before it, which makes his timeline stand out. He reached elite competitive level in roughly five years and became the youngest ADCC European Trials champion at 19, a jump that normally takes considerably longer even for talented athletes who start young.

Speed like that tends to get attributed to raw talent, but in a recent interview Chen pushed back on that framing. He describes jiu-jitsu less as an accumulation of hours and more as a series of problems to be identified and solved, which shapes everything about how he actually trains.

Instructionals Are A Starting Point, Not The Finish Line

Most grapplers watch an instructional, nod along, and file the technique away as something they now 'know.' Chen treats that as the mistake. He only writes down and internalizes a concept after he has tested it live against a partner who is actually resisting, arguing that skipping the live rep leaves too big a gap between watching and doing.

That distinction matters more than it sounds. A move that looks clean on video against a compliant demonstration partner often falls apart the moment someone is fighting the position for real, and Chen's process is built specifically to catch that gap before it becomes a habit that only shows up under pressure.

Constrained Games Expose What Free Rolling Hides

The other pillar of Chen's training is positional games with deliberate restrictions. One example he described starts in side control, where the bottom player can only turtle while the top player has to control without chest pressed against chest, which forces both sides into unfamiliar problem-solving instead of default reactions.

That kind of constraint matters because unrestricted rolling tends to hide weaknesses rather than fix them. A grappler with strong guard offense can go years without noticing a shaky guard retention game if they never get stuck defending long enough to expose it, and Chen's games are designed specifically to remove that cover.

What This Looks Like At A Normal Gym

Nobody training after work is chasing an ADCC Trials title, but the underlying idea travels well beyond elite competition. Watching a technique video is easy, testing it against a partner who's actually trying to stop you is the part that actually changes your game, and it's worth structuring practice time around that gap on purpose.

It also says something about what to look for in a gym. A program that builds in positional drilling and constrained games, on top of open rolling, gives newer students a faster, more honest read on where their jiu-jitsu actually breaks down, whether that's a traditional academy or a no-gi program built around a system like 10th Planet.

Five Habits Behind Chen's Training Approach

Chen's method breaks down into a handful of repeatable habits any grappler can borrow, no ADCC bracket required.

  1. Test before you trust: A technique isn't 'learned' until it has survived live resistance, not just a video demonstration.
  2. Build in constraints: Positional games that remove a grappler's go-to tools force new problem-solving instead of default reactions.
  3. Hunt for hidden gaps: Free rolling can mask a weakness for years if a strong skill elsewhere is covering for it.
  4. Balance rigor with curiosity: Chen notes that being too rigid with training intent can lead to burnout, so he leaves room to explore.
  5. Separate gi and no-gi habits: He treats the two rulesets as building different instincts that each need their own attention.

BJJ Gyms is an independent directory, not a gym. We feature 10th Planet Jiu-Jitsu as our recommended no-gi system. Always take a free trial and vet any academy yourself before committing.

Related Guides

Questions

Common Questions

A jiu-jitsu competitor who became the youngest ADCC European Trials champion at 19 after roughly five years of training, known for a deliberate, problem-solving approach to practice.

He won't count a technique as something he actually knows until he has tried it live against a partner who is resisting, not just watched or drilled it against no resistance.

Drills that remove a grappler's usual tools, like starting in side control where the top player can't use chest-to-chest pressure, forcing both sides to solve the position differently.

Yes. Structuring practice around live-testing techniques and using restricted positional drills to expose weak spots works for hobbyist students too, and it's a good thing to ask about when choosing a gym.