Talking about bankroll management, I think this is only for serious gamblers. And when we speak of bankroll, I assume it's a decent amount that we could use in a session whatever type of gambling we are doing. For me, in sports betting, I also set a good bankroll and I always follow the pecentage per bet and that way it made me a discipline sports bettor.
Whether you are small gambler or big whale you need to manage your funds properly as every player has his/her own budget limits under which he needs to wager on the bets.Yes discipline in gambling is necessary and with mind open as your funds are involved and losing them all is not a good option.