At 10th Planet Torrance, Professor Marvin Castell and Coach Kay are doing something a little different from the standard belt progression. Inspired by the Lucha Libre ranking system, they inserted a gray belt between white and blue, and their reasoning is grounded in years of watching students struggle, stall, and walk out the door.
The decision came down to one observation: blue belt is where people quit.
“Blue belt’s very hard,” Castell said during a recent episode of the Grappling Monthly podcast. “That’s what people don’t want to believe, but it is.”
He has watched too many practitioners receive a blue belt after a few months of training, only to get chewed up by more experienced blue belts and lose confidence entirely. The gray belt is designed to close that gap.
Under their system, the progression runs gray, then white, then solid gray before arriving at blue. The gray belt, which Castell calls the “gray wolf” phase, is treated as a proving ground.
Students are expected to know specific techniques, survive harder rounds, and begin learning leg locks before they ever put on a blue belt.
“Now we figh ting,” he explained. “Now I’m going to be having you go up against the hardest guy in the room.”
The payoff shows up on the mats. Students who come out the other side of the gray belt gauntlet carry that foundation into blue belt competition.
“You’ll roll with one of my blues and you’ll be like, ‘Damn, this guy rolls like a brown belt in the leg locks.’ It’s because he learned it at gray.”
Coach Kay added that the process also gives white belts time to mature physically and mentally before they face the full intensity of upper belt training.
Importantly, the gray belt does not transfer. If a student leaves 10th Planet Torrance and walks into another gym, they revert to white belt. Castell is fine with that.
He said, “I bet you though the other gym would be like, ‘Damn, you got skill. I should give you a blue belt.'”
The gray belt also addresses the injury problem that plagues early training. “White belts get hurt so fast,” Castell noted, pointing out that the intermediate stage gives newer practitioners time to develop movement patterns and body awareness before being thrown into high-stakes rounds.
The goal is not to hold anyone back but to make sure that when a blue belt is handed out, it means something.
“When they get to that blue, they know they are a blue belt and they don’t want to quit.”
For Castell, the whole system reflects a broader philosophy: jiu-jitsu should make you capable of protecting yourself and the people around you, and that takes real time on the mat, real drilling, and real pressure.
