The Jordan Rules was a Detroit Pistons defense that was designed to stop the great Michael Jordan from the Chicago Bulls. It was created by the great Pistons point guard Isaiah Thomas and one of the Pistons assistant coaches. I believe Brendan Malone and this defense was designed to let anyone else beat the Pistons besides Michael Jordan. Which meant anyone else from the Bulls could beat them and have big games which of course didn't happen pre-1991. Whether it was Scottie Pippen, Horace Grant, Bill Cartwright whoever it might be.
This all came about because in the late 1980s the Pistons and Bulls, Detroit vs. Chicago which is a great sports rivalry because of those two big cities to begin with and that they are fairly close together and they met in the NBA Eastern Conference Playoffs four straight years from 1988-91. Two very physical and good defensive teams meeting in the playoffs to go to the NBA Finals. So these series always meant a lot and this was a time when the Pistons were looking to win their first NBA Championship after coming very close in 1987 and 88. With the Bulls looking to take their place and jump ahead of them.
The Jordan Rules itself were fairly simple. Again anyone but Jordan can beat them meaning anyone besides Michael can take open shots and get good looks at the basket. Now they still have to execute and take advantage of those opportunities. But when MJ has the ball at least two guys on him every time he tries to drive and keep him off of the wings where he got most of those incredible dunks. Force him into the lane and to go up against the Pistons big men where he would either take a hard foul. Or would just be stopped with the Pistons getting the ball back.
And the other thing being make MJ work on defense. Whoever he is guarding in the Pistons backcourt. Or if he's guarding Mark Aguirre the Pistons small forward. Make MJ run through a lot of hard screens from either Bill Laimbeer, Rick Mahorn, James Edwards or Dennis Rodman. And give Jordan's man a lot of shots and good looks at the basket. So MJ doesn't have anytime to rest on the court. And pre-1991 before Scottie Pippen became the great player that he became the Jordan Rules was the only successful defense against Michael Jordan.