Self-control? is the characteristic of most gamblers and they struggle to get rid of it. That's why there are so many gambling addicts because they don't have this quality. I know very few people who can do something like this. The second is the perseverance in maintaining Self-control because others only manage to control themselves at the beginning, then, in the end, they also give in and lose control, so the result, in the end, is still a loss, or money which turned into stone.
Self-control is a choice as it's a psychological thing that needs the determination to possess. It is truly a characteristic, a positive one at that, and no player that possesses it would be going astray against their will and their playing plans. Those people you know lack self-control because it is not about what they say, you should know through their playing character.
And as you know the ones that are addicted, I know too, but I also know those gamblers that are disciplined and not being controlled by the game, which includes me.