I’m sorry my friend, but I believe that in gambling there are no professional players, this is because there is no system and no strategy to play and always win. It is well known that however high the prediction on certain matches, no result is always completely guaranteed.
Anyway there are and there have always been scammers who win with the football-betting system, i.e. betting by knowing the outcome of the match already before it has been played, this is because these “people” fix the game by cheating, but this is called offense!