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.
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.
However, a casino isn’t interested in giving you a zero expectation game. In order to gain a profit, they have to add in a couple of extra green numbers to alter the odds in a roulette wheel. Now, when you bet black or red, your odds of winning the game are 18?38 instead of 18?36. So your even cash bet moves to a zero expectation from a negative expectation.
Whenever you are the underdog (like in roulette), your wager carries a negative expectation and you should expect to lose some money. However, you may defy the bad odds in the short run and win, but eventually you will lose. Most bets have a negative expectation since the house does not give true odds on the payouts (just like in the roulette). Craps gives another great example. Say you want to bet that the dices will total seven on the next throw and you are paid 4 to 1 if you win. Even so, the true odds for this event to happen are 5 to 1 (6?36).
The difference may not seem like a major change, however, the house edge on this bet is a whopping 16.67 percent! And you should know a negative expectation bet for a player is a positive expectation for the house. (The casino gets an average of $16.67 for the $100 bet in the preceding craps example.)
In the positive expectation bet, the tables are now turned on the casino so that the gamblers have the advantage. Most players can’t believe casinos really allow a positive expectation game for the gambler, but astonishingly, some are out there. One good example is the tournaments, where, in most situations, more prize money is paid out to the participants by the casino than is taken in.