How is this not a scam?
I mean that seriously... How can you prove this isn't rigged?
Even if you believe their public winner based on hash of terminal block.... Could they just select a different block? You don't know the size of all the participants. So you could win but they could save the pool is very small etc etc etc
If you really want to gamble on the chain, wouldn't a public smart contract on etherium be better for this?