What’s ironic to this casino was they are claiming that they are the first decentralized casino yet they still let users create an account and deposit on it first that makes it still centralized because they have control on the users funds.
I don't know how decentralized casino, sportsbook truly works but I never seen a gambling platform which is decentralized and there are no centralized developer team. Even with bitwinup there are some sort of control from the developer although the transactions are happening on chain.
I don't think calling a web3 casinos as a decentralized casinos is true to its core. They're more like a semi-anonymous casino, where player does not need to provide ID and can conveniently connect through wallets.
However, much like you said, some elements are still centralized. They still pool funds [and I assume they have full control of this pool] to take from loses and pay the winnings, and they still collect sensitive data like device fingerprints and IPs to identify abusers, of which the data [I am somewhat sure] are stored centralizedly.
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Is there a 3rd party who can verify their claims, surely something like that must exist.
OP, if perhaps the discussion here is a bit unclear to you due to your unfamiliarity with CasinoGuru and other arbitrators, they act as a mediator where casino and player can share private information in confidence to get situations sorted out.
Many casinos prefer to get things resolved through such platforms when they have to provide sensitive data like their method of detection, their findings of multi-acc, or KYC-related issues due to an option that's offered by the platform where evidences can only be seen by limited eyes.
As such, as other suggested several times on this thread, perhaps you're interested to escalate things to CG, and sportbet.one's team are willing to share their findings with the arbitrator to get validated and verified.