Yesterday I rolled with a guy who weighed 300 pounds and only has a couple of weeks training max. I weigh 150 pounds. This guy was exactly twice my size. Needless to say the guy fucked up my shoulder. Not too serious, but I couldn't roll for the rest of the day and it will probably hurt for a week or so. I learned my lesson and I will not be rolling with bigger guys with no experience. Bigger guys that are really good are another story. They know their limits and won't hurt you. This guy was just trying to tap me out any way he could and now my shoulder hurts like a mother fucker. Lesson learned.