Odds at online casinos are set according to how much money it’s management gives and takes. The motivation behind granting better odds to players is, likely, to keep the player coming back. The motivation behind taking more from the player is, likely, that the casino must meet it’s income goals.
Each online casino should have different odds programmed into each game, based on the desires of management and any 3rd party company that oversees its gaming fairness.
A good measure of an online casino’s odds is found at their website, under “payout percentages,” eCOGRA, or “Game Fairness.” These stats are supposed to be regulated by a third party and should be trustworthy. Sometimes payout percentages will show that a casino pays out less than 80% of what they take in on a specific game.
Most of the time payout reports say that all games are paying over 90%. Odds at 100% for a game, would mean all credits paid out to players equals all credits lost by all players who have played that game.
When a casino takes considerably more than they pay-out in one month, they may make up for this by paying out a generous percentage the next month. Granting higher than normal odds in a time span could help them meet the conditions of their licensing agreement.
For players, it is best to play the game with the best odds shown on the most current payout percentage report. It may be that the casino has yet to change the odds and will keep the same payout until it is manually changed.