Sports Journalists are people who write about and/or talks (using the radio, internet, TV, etc.) about a specific sport or many sports. Fans who aren't writers or not on the professional level, may not be considered journalists but could be regular listeners to a sports talk radio show, regular attendees to a game, and/or a regular call-in-guest for a sports show. Journalists are also fans of that sport or many sports since they enjoy watching it enough to write and/or talk about it.
At this point in my life, I believe I belong to the sports journalist/fan because I feel I am more knowledgeable about sports than I am in any other subject. I feel I can connect with more people talking about basketball or football than I can about politics or the economy (since I have little to no idea about and honestly don't really care about what is happening in those categories.) I love watching sports to the point where it's the majority of the things I watch on TV.
If I were to take a guess on how I got into sports, I would say, it's because I grew up with everyone watching sports. My oldest brother was always on the phone talking to someone about a game before the game, during the game, and after the game almost all the time. My brothers would always be playing against each other in some sports game. I wasn't really into sports until high school so I guess, it's because of my brothers that I grew into it. It's because of them that I am majoring in journalism and have a Sports Talk Radio Show now.
I think you gain authority and power in Sports Journalism by the more you know about a specific sport. Sure, a lot of people say those journalists "don't know that they're talking about." But there's a difference between having a different opinion and perspective of what happened and not knowing what you're talking about. Here's an example of having different opinions and perspectives. One analysts says the basketball team lost because their star player shot too much while the other analyst says that the star player shot a lot only because the rest of the team didn't make their shots. They both know what they're talking about. They just have a different outlook.
You would never hear me talk about NASCAR because I barely know anything about that sport. Usually during the radio show, the last 10 minutes or so is my co-host talking about things that are going on in NASCAR while I stay silent during the whole segment. I stay silent to avoid saying something stupid due to my lack on knowledge.
If you want to be a Sports Journalist, I think success is being able to be able to write for a newspaper, be a commentator for a team, or just being on TV talking about sports. For a fan, it could be the opportunity to watch the games, have their voice be heard on the radio, and maybe even be on TV as well.