My first gi jiu jitsu class, I was able to hold full guard top position on the brown belt instructor for about 5 minutes before he got bored & gave up. He was about 5’10 170 & I was 6’6 230 at the time so had a huge size & reach framing advantage. My goal was to not allow him to do anything he wanted & I succeeded, no sweeps no subs, just fails. Switched gyms after that to find some bigger training partners & got to learn a lot more. Size was actually much more of an advantage than I thought it would be in jiu jitsu