Odds are very similar to dice, 50/50. I don't think there are patterns in general since it would be easy for long-time players to recognize them and take advantage. But even without a pattern, the chances are still way better than any gambling game. This being said, though, it can get more addicting. And then you'll notice that even if there are good odds, you're more leaning on losing than actually winning with your 50% chance. Added to the fact that, mostly by instinct, people tend to gamble more when they face losses.