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Caleb Khan - Head Brazilian Jiu Jitsu Coach

Caleb grew up in the East Bay and wrestled at Albany High School. Soon after graduating, he began training Brazilian Jiu Jitsu at Ralph Gracie Berkeley under the tutelage of Dave Clahan (one of Ralph's first black belts) and Professor Eduardo Fraga. Caleb received his black belt in 2015, and has competed in numerous BJJ competitions around the country. Caleb's fascination with health and the human body inspired him to major in Kinesiology in college at the University of San Francisco. Everyone practicing jiu jitsu at Guardian is extremely lucky to have Caleb's expertise as they continue on their martial arts journey.


Michael Clark - Brazilian Jiu Jitsu

`Mike grew up on a family farm in Iowa and was overweight most of his adult life.  Brazilian Jiu Jitsu helped him get and stay fit. Mike has competed and trained on four continents, has medaled at some of the biggest tournaments, and has competed in three professional matches. He received his blue belt and purple belt from Brad Nicolarsen at the Kompound in Colorado, which is an affiliate of Rafael Lovato Jr and the Ribeiro Jiu Jitsu lineage.  When he is not on the mat, Mike is a Product Manager at Facebook.


Jim Cotter - Brazilian Jiu Jitsu

Jim started wrestling in 1996 and coached at various high schools for 6 years. He received his blue belt while at the original Ralph Gracie San Francisco Academy, received his purple belt from Cassio Werneck in Sacramento, and received his brown and black belt from Darren Uyenoyama at Faito Tamashi Combat Club in Daly City. On the mat you can spot him in his dinosaur rashguard or pink gi. Off the mat you can spot him in his dinosaur rashguard or pink gi.


Calder Powers - Brazilian Jiu Jitsu

Calder teaches Jiu Jitsu to youth students and adult members at Guardian. He received his Purple Belt in Jiu Jitsu from Eduardo Fraga in 2017 and competes regularly. Calder found Jiu Jitsu when he was 18, at that time he was struggling with finishing high school. When he moved to Santa Cruz to attend community college he adopted Jiu Jitsu as his passion and it helped him grow in discipline in other areas in his life. While finishing his degree at UC Berkeley, Calder worked with Co-Founder Ben Kovacs to create a community college scholarship called Powered by Guardian that gives financial assistance to students at Guardian so they can follow a similar path of working hard in the gym and the classroom to create a brighter future for themselves.