If you are a league follower, know the stats, who is in form etc, this not a gambling!
Gambling is when you play roulette and anything can happen.
According to you which is not predictable, that is gambling right. Means the Roulette, Dice, etc. games are unpredictable we can not guess the result. So these games come under gambling. Then what about sports betting? Here also we will put money in risk and now we are getting unexpected results frequently. I think both are same but for you what change you found I don't know.
Honestly in sports betting it is not 100% that you can win but you have 75% that you can win in sports betting because you can choose what team is giving high performance than his enemy.. but you can be still lose because sometimes bad luck comes to us and the team we are choosen can be lose..
So for me sports betting is gambling because you are betting your money there .. roulette or dice game is just another gambling game..
Every game with money involve and bets.. we can call it all gambling..