Yes I think winning bet is totally depends on luck. But everyone tries their best to win bet. But winning bet becomes very difficult when one bet without understanding the games. I think we should have good idea before gambling. We have to bet later. And if we bet without a good idea, our money will be at risk.
every gambling activity even though it is a sports bet which can be predicted also still depends on luck because sometimes the underdog team can still lose even worse if we bet on sports we don't know about and only bet on underdog teams. maybe if we are lucky we will get a win but if not, it's just like a casino game.
so the reason is clear enough that we always bet on certain sports because we always do an analysis before betting to get a win and on the one hand if we really want to try betting on other sports we can try our luck with a small amount of betting on the favorite team.