There is people that make a good living by gambling in sort bets. It's not the same as full on gambling, you can really study hard teams and their statistics and try to decide what to do. In the roulette or slots or dice, you cannot research anything contextual beyond pure raw statistics of the amount of times you play.
Honestly in my own i can't live in gambling because there is no assurance that actually you can make a good earnings in gambling.. maybe for others but i think they are no always win and make a good profit in gambling it is too risky that you can gamble there with large amount that can gives you large win profit if you lose you can be lose a large .. Everything in gambling is more on luck that skills or experience..
I also confused to know who are these people who are rely on sports betting for their living. Sports betting is also part of gambling where we put our money on risk how can we get assurance of guaranteed profit. Sports Betting is combination of experience and luck but we have chance to make profit.