I'd say it's mostly luck and some skills for that to happen. It's not 100% chance that you will win if it's only skills because no matter how skilled you are is that you may still failed. As many other people would say that when it comes to gambling is that it is all about skills and luck combined except gambling games like slots which is purely luck. Having skills is what makes your chance of winning increase compared to depending on luck alone.
Agreed, luck is needed despite the type of gambling that you're doing. It doesn't matter if it's sport betting or any other type of bet. You need to be skillful too and not depending only on luck for you to make profits after gambling for a long duration. I can't say anybody can depend on only the skills that they have for winning either, you'll need some atom of luck because there are times that you would have made the wrong decision and you need a little bit of luck for things to change. Your skills are going to increase your chances of winning but that doesn't guarantee you that you're going to win. Lasting gambling is all about being lucky then other things help you out a little bit.