Bankroll
A bankroll is the total amount of money set aside for betting and treated as separate from everything else.
In plain English
Its purpose is boundary-setting. A defined bankroll makes each bet a fixed fraction of a known total rather than an open-ended decision, and makes a losing stretch survivable by design.
Example
Setting aside a fixed amount for a season and sizing every bet as a small percentage of it.
Why it matters
Most catastrophic betting outcomes are bankroll failures rather than selection failures.