But with many bitcoin casinos the operator can claim an ultra low edge to drag in volume but the actual edge would be multiple times that if they aren't playing fair.
Totally right. You bring up another really good point. Using shufflepuff, we can feed it a truly fair roulette wheel (36 cards) playing red or black and still optimize the initial deck in a way that favors the house.
After a few minutes:
000000000000000000111111111111111111: 2496
000000000000000001111111111110111111: 2500
000000000000000010011111111111111111: 2526
000000000000000010111111011111111111: 2533
000000000000000010111111110111111111: 2538
000000000000000010111111111110111111: 2545
000000000000000011111111111110011111: 2546
000000000000000110111111110110111111: 2549
000000000000000110111111111110011111: 2553
000000000000001010111111011110111111: 2560
000000000000001010111111110110111111: 2565
000000000000001010111111111110011111: 2569
000000000000001110111111110110011111: 2573
000000000000010110111111110110011111: 2577
000000000000011010011111111110011111: 2581
000000000000011010111111010110111111: 2584
000000000000011010111111011110011111: 2588
000000000000011010111111110110011111: 2593
Anything above 2500 actually favors the house, despite the cards being in a "fair" distribution (18 red, 18 black).
Granted, advertising a 0% game would be silly and raise red flags, but an ultra-low edge would work well.