I have the believe that success in gambling requires a mixture of luck and skill. This is opposed to some people that believe that gambling is entirely a game of luck and others who believe it is entirely a game of skill.
There is no gambling games which is 100% based on skills, even in sports betting and pvp poker, luck is still taking a big part in the outcome. I wonder who are those people who believe that there is a gambling game which is entirely game of skill? You can be very talented and skillful sports bettor or poker players, but when you are out of luck, your skills and knowledge cant give you a win.
Your right, there is no skill that is relatable to gambling. A person may be lucky to predict and unexpectedly win bets but not because that is his skill but because he is lucy and irrespective of someone has to do thorough analysis on bets gambling mostly all about luck and chances. I have seen good video games player, but they do not know anything about gambling. So, you won't judge someone because he has little knowledge on spots, video games and get recent happenings on all sport events. You don't expect him/her to be good at gambling. Gambling is mostly luck but at a point there are persons that do proper analysis and follow up sport information and sometimes predict games that are correct especially in football.