Already from both phrase, Bankroll and Management the definition should be clear. Bankroll won't help you win more to stay longer, the reason for managing bankroll is to help us balance between having gambling as entertainment and not having to overspend after consuming what was supposed for gambling.
Most gamblers that became addicts are due to failing to manage their bankroll, there is always urge to keep gambling, the only thing to refrain us from continuing gambling is bankroll management, everyone who lacks such quality becomes compulsive gambling and will face serious financial difficulties.
It's just that most gamblers or bettors don't know their expenses and income. And because of this, when they get paid or make a successful deal, they think that the entire amount that is now in their hands can be spent on entertainment. Although in reality, of course, they have their own expense items such as paying for housing or buying groceries.
Therefore, you must always be responsible to your family and, first of all, to yourself, and know what remaining income you can spend on entertainment.