I don't really understand why "provably fair" would be so big deal. The house is winning always, no matter what. But I don't gamble myself, so perhaps I don't uderstand that world that well.
My gut feeling is that since it's using a repeatable number-generator (without which it wouldn't be "provably fair" as you have described), it might be possible to game by client-side pre-evaluation of the sequence. Even if the whole sequence isn't finalized until the initial bitcoin transfer is made (I only have the information provided on the site to go on...), it might be possible (for example) to strategically transfer/commit, at a known/manageable cost, but simply not play the hand (abandon the transfer) unless the payout is greater than your expenses, circumventing the game's long-run behavior entirely. We don't have server code to look at (github?), but we all have access to python's libraries and can seed our own PRNG after the transfer in order to evaluate the hand/sequence.
Not exactly. It means, you can check two things after you have played:
1. The random number was generated before you even started. So the house could not change the number depending on the actual bets.
2. Distribution of random numbers over time. E.g. if the rule is "win when uniformly random number 0..1 is greater than 0.5", then you can check the history of all random numbers played (at least with your bets, if you don't trust the house to show real bets for other players) and calculate the properties of actual distribution. If it does not contain a significant offset, then it's fair. (Small deviations can be seen simply as part of the fee.)
I know what probably fair means, just that I don't understand why it would be so big deal. Why would the casinos cheat if the probabilities are on their side in every case?
i guess because things like 888casino are not provably fair you just have to take their word for it that it really did come in as red 8 times in a row taking all your money, at least with provably fair you can see how red or black are determined and then confirmt hat you were not screwed becase you dropped a big bet on the table but you were screwed by random chance.
I guess with bitcoin being so anonymous, it would be easier to get away with fraud and never be caught compared to a company that accepts USD though VISA.
it's all about reputation. all games are made public online. all payouts are displayed on the website. if things went array for any reason it would be public knowledge very quickly and thus the end of the site.
I like the idea of provably random, but I think I would change it in a subtle way: I would pull the least relevant digits from a list of stocks (or currencies), sum them, then hash them. The key would be to do this after the bets are placed. Since any amount of jitter on the least significant digit for any of the stocks completely changes the outcome, and since there are already massive third parties interested in the exact nature of these numbers, you would have a very random, very provable flip. You wouldn't need a changing seed because the bets would come in and then everyone would wait a second or two and then the result would be provably fair.
The problem with your provably random method is that it is still possible for the house to get a slight edge. Since the server seed is random, you could regenerate it hundreds of thousands of times so that the house has a slight edge for the first two or three flips (assuming there are lots of people playing on the same deck, it gets wayyyy easier if it is one deck per person). You don't need that much of an edge to dominate your competition. An edge of 2 or 3% doubles your revenue; which would 4x or 6x your profit, since margins are usually thin for gambling sites.
Provably fair means you know exactly what you are dealing with before you start. Game payout odds are clearly displayed in the payout table.