Let me tell you a story
An illegal betting machine in a private club. I am a member and am expected to give free minor legal advice but charge if much money is at stake. I have an in. The club does not open on Wednesdays. Cards dealt were from a single deck. S17 DAS. Shuffle after twenty five cards. Four places. Possible bets .25 to $100.
I took a Wednesday off and recruited two friends. Got the key and the understanding I could leave credits on the machine and would be paid. Took $3000 and Griffin and the friends. Did everything perfectly.
After about four hours of perfect play and breaking about even and observing dealer hands had seen too many 5,6 combinations. Quit.
Footnote: I also represent the owner of the machines and the guy who works with him who dealt with the chips. After I had tried to take them and could not I told them. They laughed. The chip had a 5,6 gimmick.
Moral: Don't gamble with other people's machines.