To be a good casino player, one has to really have the mentality of ... well, that of a tiger-dragon hybrid I suppose - carrying the aspect of the tiger, so to speak. Those that check whether one has won or not probably ain't under this aspect, while ones who check whether it was a good decision or not are of this type.
It's indeed really seperated by personality and initial traits of the person - not "intelligence level" - that word blurs much up as it is a large mixture of further mixtures, so to speak - too commonly used, also, yeah. Like other activities, gotta be a cat to catch preys, not a rhino - rhinos can't really catch preys - they melee fighter bettah.
Those that react based on wins or losses (the reports, the feedbacks), and not on the actual feed back - reports of evaluation and assessment of those decision making bound to not be a good casino player.