In most cases, the payoffs strongly favor the house, even so, some freaky situations arise that offer astute gamblers an edge.   In order to understand the edge you must understand the expectation, and then you can start winning at online casinos.

Zero expectation

A zero expectation bet simply has no edge – for the player or the house. This balance implies that both sides can break even in the end. For example, if you eliminate the two extra green numbers from a roulette wheel (0 and 00), the game now carries a zero expectation since it has 36 numbers, 18 black and 18 red. Any bet on black or red would be a zero expectation bet. Put differently, when you bet on a certain color, your chances for losing and winning are equal; it is just like flipping a coin.