Okay I'm coming to the right forum this time so hopefully I get actual insight. I recently started training at a local gym (Bed Rock) and have no belt in bjj. I rolled with a couple of guys there in BJJ and honestly they weren't very good. I actually was better then a lot of them believe it or not. Since then I've been training with my buddy who use to train there but stopped when he won a bjj tournament. He said the only guy who tested him there was the coaches which tells me I would be wasting my time there. When we grappled I went for submissions and actually almost had him a couple of times but he had good defense. I attacked to many times for submissions he ended up catching me. This happened two times (I got submitted pretty quickly the second time) because I was very impatient. The third time we rolled I decided to be patient and not force anything. He went for a lot of submissions but I defended them all. The problem that I had was when I was on bottom and he made a mistake or got tired when attempting a submission I was defending well I had a very hard time taking advantage . For instance he got my back and attacked my neck but I grabbed one of his arms and grabbed my wrist and tucked my chin. I could tell he was really tired so I exploded to get on top and be in his guard but he scrambled and was too heavy for me to keep the position. I said, "damn if you weren't so heavy I would have reversed you". He said, "It's not the weight it's my scrambling from wrestling, that's something you can't teach". I weight 160 and he weighs 210. I'm not saying he couldn't teach me new things but I feel like a lot of the reasons why I couldn't finish him and take position was due to his size not his skill. After we were done he even said our bjj was pretty even. So from people that have more experience grappling different skills and sizes do you ever grapple a bigger guy that you feel you have better technique then but you just can't implement it because of his size? Also if you were a really good black belt would you be able to negate such a large weight advantage?