American mathematician Edward O. Thorp is the father of card counting.[47] His 1962 book, Beat the Dealer, outlines betting and playing methods for optimal play. Although mathematically sound, some of the methods not apply, as casinos took countermeasures (such as no longer dealing with the last card). The counting system in Beat the Dealer, the 10-count, is harder to use and less profitable than later systems. A history of how counting developed could be seen in David Layton's documentary film The Hot Shoe. However, when you've two cards which might be the same—e.g., two 8s or two jacks—most casinos allow you to cut up them into two separate arms.