This is really a very good approach of gambling if all the addicted gamblers can adopt it, it will help them reduce addiction and even if any other gambler both new and old adopt such method, they won't face the risk of addiction. Anytime I go gambling, I always allocate the money I can afford to lose, after which, I don't make any other deposit.
It seems simple when you are not playing, but when you get excited and when you have lost everything that was on the deposit, then you begin to perceive everything differently and want to get back what was. It would be reasonable to stop so that the emotions calm down, but if the desire to win back is stronger than common sense, then the deposit is replenished again, or maybe if there is money on the deposit, and you were going to stop earlier, but instead you continue to play further. Even if you need to stop, it is not always easy to do.
Using amount that you can afford to loose is the core of responsible gambling, it's easier said than done but with discipline any gambler can adopt the strategy. It is the best way to gamble if you don't want to have regrets when you lose because loses normally occur more than wins. Based on your financial capacity the amount that you choose to gamble with determines the level of risks that you're willing to take. It is advisable to reduce risk because winning is by luck, strategies can help you to minimize the chances of loses but it's not enough to make you win.