We have been working on a handy verifier for the selection of who spun the jackpot wheel. It is based on multiple random factors like bet size, usernames participating in the round, and bits from the round hash. Rounds can be verified here: https://jsfiddle.net/kyawgjmv/embedded/result
Except that's not what provably fair means. You can directly control who wins the jackpot, if you have a house-player. And there's absolutely zero way for people to have any idea if you're doing it or not.
That's not bad per se, and doesn't mean you're cheating. But it means it's not provably fair. Full stop. Any attempt to market is as provably fair is dishonest.
If the house can predict multipliers in advance, they can cheat without getting noticed by reducing the player’s EV. Auto cashout limits the round win to a percentage of the bankroll, so if a round that will go high is coming up, the house can just place big bot bets on this round, forcing earlier cashout for the real players.
Actually you have a (small) point. In bustabit for instance there's a "forced cashout" when the server will cash people out due to a per-game stop-loss being hit. And you're right, this is not provably fair. But it's also why bustabit tries so hard to make it so hard for this to ever happen. Like such that it it doesn't even accept single bets that could trigger it. I suspect it hasn't even happened at all in the last year, so in reality it's just not a real issue. But you're right on this point. But there's several orders of magnitude difference.
Even if the house knows multipliers, there is still no guaranteed way to cheat, as higher bet chance is limited (win chance is normalized by bet amount) and users sorted before draw. So as long as players can freely join the rounds that win jackpot, the house can only increase own win chances, but not guarantee the win). In addition to that, it is up to the bankrollers to benefit from this scenario since the house would essentially become a high-roller
I think you're smart enough to know this is technobabble. Before the round starts the house has all the information it needs to know who will win the jackpot. It also has the ability to control who joins the rounds (which dictates who wins). It can *very* easily add extra players and modify the bet amounts such that the house player wins. The house can trivially brute force even a million combinations in a fraction of a second to find out which combination will result in the house winning, and then execute that one.
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Anyway your response to this is extremely disappointing to say the least. There were two obvious ways to correctly handle this situation:
a) Make the jackpot provably fair
There's a few ways to do this, one neat way would be run a verifiable-delay-functions on the game player bet list, where each client also sends a randomized seed with their bet. Then if the game goes over XXX you use that result to calculate the jackpot winner.
b) Just let everyone know "our multipliers are provably fair but our jackpots aren't! it's just a bonus"
but instead you've decided to go down the third pat, and just spout nonsense and misrepresent it as something it's clearly not. I would encourage people to not play here until your marketing matches reality.