There was a girl I trained BJJ with. She was about 130 pounds and she trained 3, 2 hour long classes a week, drilled at open mat, and took a private lesson - learning nothing but joint locks and escapes on the ground. It took her about 6 months to be able to beat regular sized men who just walked in through the door. About another 6 months and she could tape trained, adult male white belts with some experience, earning her the nickname "gate keeper." So, for her, about 200 hours of training to tap larger, untrained people. You are in for a surprise if you think you are going to tap a larger person out with a joint lock you practiced for 10 minutes on a compliant partner.