Yes self control is a must in the world of gambling as we all know that every time we bet there's a greediness will come to our self that dictate us to bet more and more even though we are encountered many losses which pretty bad once we loss and bet more then loss again. So it's better to have self control for the sake of addiction because once we don't have self control then addiction can take over us easily.
Gamblers can make the decision to have self-control or not in gambling, they have to be conscious of the way they gambles not to affect their physical and mental life and people around them, it's not something that should be expected seing that people are always complaining of our gambling lifestyle, we have to be very careful not to constitute the irresponsible gamblers around making it so discouraging being a gambler.
It is not only about gambling, in every sphere of Life whatever thing you do you need to have self control and at least at a particular time, you need to have self appraisal to see if you are making progress or you are heading the wrong way. Most gamblers does not have time to re-evaluate their life and their spending habits. It is only when it has gotten to an extreme that they will understand that they have deviated. That is why married people should always make their wives know about their spending habits, especially gambling if it is possible because it is the wife that he moderate them when they are going extreme.