I was an extra in the Castle scene! I met Jason England before I ever knew who he was! I had no idea at the time that this guy was the one doing all the card sleights that you see in the film!
Actually there are some lines in Shade that are based on dialog from The Cincinnati Kid. A previous film that is closer to Shade in principle is A Big Hand For A Little Lady.
Both the Kid & Lady are classics that you should watch if you're interested in the world of gambling & cons.