It is absolutely central to gambling. It is not necessary to learn the math provided you can accept the simple facts presented in this segment. Probability will not dance to your tune. In Zen, the practitioner learns not to go against the flow.
Probability is a great ally but a terrible foe.
Don't fight it. It is an area of ignorance for a surprisingly large number of people and is rife with popularly accepted myths and fallacies. A smart gambler understands that blind chance does not play favourites, does not recognize 'lucky numbers', has no memory and no personality. It doesn't care whether you tap a card before looking at it or what amount you have placed on an outcome. Confusion sometimes arises because of the different likelihoods of a given event occuring before it starts, compared to part of the way through the event.