I think it's valuable to at least have some extremely basic knowledge of these topics, to allow you to barely follow along when someone brings up sportsball or TV shows. You don't need to know specifically whether or not the Eagles played basketball with the Phillies last night or what the score was, but you should know at the very least that the sentence doesn't make sense. Don't fight these topics, don't constantly try to change the conversation into something [likely only] you are interested in. And definitely don't disparage the topic, convey your irritation, or just sit there looking bored. Just kind of be a neutral observer when you're not into the topic. I used to be that insufferable "Area Man Constantly Mentioning He Doesn't Own A Television"[1]. It's cringe and it's not going to get you anywhere socially.
Agree with not disparaging, but disagree with having to know about the topics. Then again, that may be a sex based difference (assuming you're male): Women might be allowed more leeway about not knowing things, particularly when it comes to things like sports.
Admitting you don't know is fine, as long as you don't insinuate that you don't know because their interests are beneath you. There are lots of things I don't know, it doesn't mean those things are unimportant.
Yes, the problem with sports (in some circumstances) is that people will think less of you for not knowing some ground-level information. On most topics (the news, TV), people are more excited to explain the basics to you, at least in my experience. If people have to explain the rules of basketball to you, they're likely to think you're an idiot.
I hate sports, and don’t really follow them. I do research standings and stuff before going out because I want to know if someone brings it up, if they’re an “underdog” kinda person or just loyal to a team. Most sports people will quickly discover that I only have surface-level knowledge though, but I ask questions and people seem super happy to tell me how things work. In fact, most of what I know about pro-sports comes from what people tell me at parties.
1: https://www.theonion.com/area-man-constantly-mentioning-he-d...