After some research... I've come to know that Docc didn't created it. It's called Mental Stud by
Henry Christ. It can be found in The Jynx by Ted Annemann, issue 71 (December 16, 1939). All docc
did was change coins for poker chips. Henry wasn't credited. For the same price you can get a lot
more getting the book so, it's not worth it. Save your money.