The idea is considering your gambling expense as something strict and not making any extra payments or deposits. Think about it, regular people save money in one way, how is that? They calculate what their cost of living is and they calculate their earnings and they manage to make some extra on top of that, not everyone is rich enough to do this and some people unfortunately spend more money than they earn because they do not earn enough but this case is for people who can save money.

Instead of calculating only your food and bills and what not, some people put 50 bucks payment for gambling too, you add that and save money that way, if you say 50 bucks and not spend 100 bucks on it then you can always save enough money while gambling as well.