For me the best way to gambling is betting on sports. If you follow teams, you know that they are surely win (there is never 100% guarantee , but it's better way than roulette etc.). You can try onehash.com. They got good rates. Some of them are unique. ^^
Yes, you are right. If we follow the particular sport, team and their players then its easy to predict the possibilities of the result. Though its not 100 % sure but we can be little bit closer and at least we can minimize the loss. Its always safe to betting on sports than other online sites.
I sort of disagree. Even the experts are right just above 50% of the time. These are guys who are watching, analyzing every detail and still only get better than 50% just barely. I would say the best gambling that you can be the most profitable on is live Poker.