It's a challenge to learn and a challenge to do it without getting caught. Its fundamentals are simple to learn and its performance is difficult to perfect. Everyone knows what it is, but very few can do it really well.
It's Three Card Monte, and since every finger-stretching card man is anxious to learn the secrets, Leo has put them down in this book. He played with the moves when he was a teenager learning the basics of card craft, but it wasn't until he saw Jay Ose work that he knew what it meant to be able to fool people with Three Card Monte.
Jay demonstrated the very important fact that you have to con the mark into telling you where the winning card is located, and if you move too fast then he won't guess. Anyone who saw Jay work will remember his charming, laconic Hoosier smile and style, but you had to watch out for the end of the routine; he'd get you every time. Through years of working in carnivals and on the streets, Jay had perfected the "look how easy it is" presentation.