Keeping a betting log is possible for those who bet only on sports... and they can have some benefits from keeping a betting log. But for me, who likes to play almost all games, keeping a betting long doesn't make sense, I sometimes win at sports betting but lose at slots (or some other lucky-based game). Sometimes it's the other way around, I lose at some lucky-based game, and then I switch to sports betting...
I believe many people likes to play more than one game, as long as we have some balance we will play some game... which one usually depends on the mood.