I think the best answer is "commitment". Yes, this is absolutely true, because those who makes a living through gambling or sports betting are always there sourcing information and past events of those clubs and teams, i mean; Before it would get to match days, they will go in research about those team and clubs that are to play and know their past records and events. I believe with all these commitments they would definitely makes out a winning.
So if you want to be involved, you need to devote your time and work very hard before you could start making a living from sports betting.