Yes I would usually withdraw the initial amount and play with the full (Or half) profit depending on how much money I need to make
This is a good gambling plan, as this way if you get huge lose streak you will not lose everything that you deposited and what you won, as some, or most of the money will be safe. Personally after i in some money, i take back what i deposited and then i continue to gamble using what i won only, if i lose that i don't deposit again, and i better continue my gambling other day
But if one is a regular gambler then all these methods will not be lost for long because winning in gambling happens only once in awhile but most of the times people lose money. If one start with only their profit money, soon or later they will lose that money, and again they will deposit back their money, and finally, they will lose all. So gambling shouldn't be an everyday activity instead just gamble once in awhile then it is a better option.