In sports betting it is different than in poker but there is also some similarity. To find value you have to make assumptions and calculations that combine mathematics and intuition. But while in poker you play against other players, in sports betting you play against the house that is also trying to find value in the odds it gives you.

From what I understand, in the old days it was easier to find value in minor sports and secondary leagues, but over time the bookmakers became aware of this and adjusted the odds better. If you add to this that at least in some countries if they see that you are a winner or they forbid you to continue betting or they limit your bets to very low amounts, we see that it is becoming increasingly difficult to find value.