If you really love a certain sport, it would be easy for you to understand things about the said sport. How most players would play, teams that are most likely to win and such. Let's say you've been a fan of basketball ever since, then you would ways watch games. It's easy for you to know what team is stronger. So if you would make a bet, you know who's most likely to win.
It's just a matter of knowledge about the sports and the players. Unlike other gambling who need luck, sports betting is more of analysis based on their history of performance.
It's different in sports betting because there are odds in every line and there's a lot of line available that will confuse a person who is knew to sports gambling. Even if you always monitor the sports you love, it does not guarantee that you have a chance to win most of the time, this is a skilled based gambling that you will have to learn over time.
Most of the popular bet are the point spread.
if we have our favorite team like the warriors and we know they will win but they have a line of -10, that line would sometimes puzzle our mind that what if the opposing team covers and we lose.