Gambling is completely based on luck, you are right, when someone has no knowledge of gambling, if he plays 10 games depending entirely on luck, out of which he may win 2 games by being lucky, but it is never a Not a reliable strategy.
The bottom line is that gambling never guarantees anyone a win, the outcome in gambling is more likely to be negative most of the time. That's why you should never gamble beyond your means, because you never know when you might win, you might just lose all day, or you might just win all day, it's never for sure.
So gamble only for the amount of money you can afford to lose, just for fun, and when you lose or win, don't gamble impulsively or greedily, and have tend to stop yourself at the right time.
When it comes to sports betting, I think knowledge of the sports plays a little role. I would say 10% out of 100% goes to knowledge and the right analysis of the game while the other 90% depends on luck.
Betteing on a game you know nothing about is not very smart because you can pick a hundred games and still to get any of them right. Your chances are way too small.
With some other casino games, like dice and the rest, it's pure luck. I don't see how you're going to let to roll a dice or stop a spinning wheel for you to win, you just have to be lucky enough, but with sports betting, knowledge plays a big role.