I would say it depends but the truth is all gambling games still have a percentage of its possible win or loss dedicated to luck.when we make gambling stakes, we hope on winning but the truth is there is always a chance of losing. Aside the fact that all gambling games still require a fraction of luck , they don't all depend equally on luck. Some include things like experience, statistics and even proper analysis which some are just fully luck based.
Take soccer predictions for example with statistics and analysis you can raise your winning odds higher making luck to be more on your side.
We can't fully go against luck being seen in gambling but experience, statistics and proper analysis of teams are also their as a good key to increase your chances of winning thereby increasing your lucky potentials. The reason why I can't put aside luck in things like this is that some good teams may play bad that week. If you selected such team as part of your game the week, that means luck isn't at your side that week. So I think all works together in gambling for success.
You're absolutely right,there are some people who are expert in prediction they keep wining over and over again,why some people always have a lucky win, reason been that they don't check statistics before betting sometimes statistics matters alot,reason is because with the statistics you can be able to know what to predict, probably if team A is at home they always beat team B or they end up with a score of draw,and also whenever time team B is at home they end up with 1:0 I think if you keep following this step you will keep winning and make luck to be on your side.