What popular opinion is a non-starter when having a discussion/argument with someone?

Meaning when you want to have a basketball discussion about a player, era, or basketball related topic and they state an opinion that you know it isn't even worth pursuing a rational conversation anymore.

A couple of mine:

1) Kobe is a top 3 player of all-time. I'm willing to listen to discussions why lots of guys who might be in someone's top 3 based upon which criteria they feel is the most important. If their sole argument is 5 rings and/or Mamba mentality. I'm out

2) The WNBA or women's basketball is a "purer" form of the sport.