Michael Jordan and the Chicago Bulls were unstoppable in the 90s. During that decade, they won 6 NBA titles and went on a tear that has yet to be matched since.
Perhaps their biggest obstacle, though, was the "Bad Boy" Pistons, who literally used "Jordan rules" to slow down the Bulls superstar on the offensive end. But how, exactly, did those rules become a thing in the first place? Apparently, they were instituted after Jordan pretty much embarrassed them on national tv.
From that point on, the Bulls vowed to stop Jordan by not allowing him to take flight. If he tried going for a drive to the rim, they would basically throw to the floor. It was a pretty extreme tactic, but it worked for a while. The Pistons would win two straight NBA Championships before MJ eventually figured out how to beat them.
Jordan broke the "Jordan rules" by simply adjusting his game so that he would catch the ball in the paint instead of on the outside. The Pistons couldn't guard him the same way and MJ was able to do his thing.
So, that's the story of the "Jordan Rules." While it was highly physical and very controversial, the Pistons thought it necessary after he smacked them on national tv. And, like most things that went up against Mike, it was broken in the end.