I will call the person both skilful and lucky!

You mentioned being successful "in the long run." This means it is not some kind of luck only, it is consistent. Fine, luck is always present in gambling, but can luck sustain you? Certainly not! This is why you give more kudos to those who are consistent in the long run, rather than believing they are there by mere luck. It must have been a good gambling pattern that is blended with good managerial skills and discipline. All these are beyond luck, but skilful.