I think the two times where I was injured and I had to seek medical attention were the worst. . the gentleman both weighed about 200# and it was in my first year of wrestling, so I knew enough to win some of the time, but not how to keep myself safe with larger opponents who are intentionally trying to hurt me. . one bruised my tailbone throwing me across the room and off the mats onto the floor (and there were other problems with this session/individual) and the other threw me to the ground, put their knee on my chest and pulled up until my sternum popped and I couldn't do anything to stop them. . those two would probably stand out as the worst. . .