I read this post and immediately thought of my own little tank. Brutus, he can get very rough in play, and even when their are bigger dogs he immediately puffs up his chest, perks his head right up and gets into this tough guy stance. Brutus has never been a fighter though, but his play is very rough at time. Sometimes to the point of grabbing a back leg in his mouth. Over time i have worked to correct this. And as soon as I see him go for the legs, I leash him again and play time is done. No need for him to be biting! His bite is very, very strong. This used to be a big thing with the bigger dogs. But now, his roughness in play is different. instead of taking out the legs, now he will run up to the dog, and throw his front paws into their side, he then pushes off of them as he pushes them and swings his butt around to them. Kind of hard to explain, but it still manages to piss off some dogs. He is about 64 lbs, and a little over a year and a half. His ribs are easily felt, and his waist is very apparent and the vets have said he is right where he should be for his size. I have come to the conclusion that some bullies just don't realize their strength or size. Big things come in little packages especially with these guys! He also tried to throw himself on top of other dogs, like he's trying to pin them. Once at petco, we ran into another bully and he was exactly the same, they were both throwing their weight around into each other but at the same time you could see it was all in good fun. Sorry, a little distracted from the post.
But like i said, what worked for me was realizing what was the beginning of the behavior I was trying to correct, or stop it before it was allowed to happen. I don't remember what it was, but their was a point when I could tell he was going to lunge for a leg, and when i saw it I grabbed his collar, leashed him, and we went on our way, dragging Brutus away haha.