1. You actually play for that new team. In this case, you must still wear the cup of your old team during games.

2. You purchased that new team. However, you must have had a damn good reason for purchasing a rival. Michael Jordan can buy a piece of the Charlotte Bobcats because the Charlotte Bobcats can’t win if locked in a gym with three pygmies. But if Jordan bought the Detroit Pistons? Bonfires of Air Jordans everywhere.

3. Your team hired male cheerleaders.

4. Your town’s law enforcement permanently banned you from coming within 500 feet of your team’s players, staff or stadium. Sure, sure, we know it was all a big misunderstanding. You were parked outside Peyton Manning’s house with a telescope and three months of detailed charts because you are his personal astrologist.

5. Your spouse cheated on you with somebody from your team. With a starter, not some backup, coach or crappy PR intern. And you had to find out by some stomach-turning means, such as skywriting.

6. Your team is approaching its 50th year of one-family ownership and still hasn’t won diddly. This is known as The Darwin Rule and allows you to escape, free of charge. Good example: The Fords of Detroit. No wonder 10 of the 22 declared NFL fan free agents at Fan-Free-Agency.com are ex-Lions fans.

Rule 6b. Your owner still wears Members Only jackets. His initials are Al Davis.

7. Your team’s home games are no longer televised. You are free to go, Jags fans.

8. Your team folded or left town. In this case, you are automatically an unrestricted fan free agent and can immediately put yourself up for bid. A writer named Scott Soshnick did this recently with every big-four franchise. Only nine wrote back. But one — the Golden State Warriors — had 28 employees send him we-want-you e-mails, mailed him a jersey with his name on it, sent a DVD with rookies wearing that jersey, signed him to a $1 lifetime contract and wrote a mock press release announcing a new fan acquisition.

9. Your team changed its uniforms to teal.

10. Your team is the Cubs. Seriously. Go already.