[duker41]

"this book was written during a period of time in which poker players had no sophisticated knowledge of percentages or strategics at all."

You must be forgetting the pages of statistics Mike Caro provides for Super/System, that Sklansky also wrote for Super/System, and that the statistical ideas used in poker have been around for a long time. That being said, Doyle's motivation may also have been something that Slim mentions in his book, a desire to be seen as an action man. They grew up in a gambling world that involved more then just poker and having a rep as a tight person wouldn't help when you're trying to sucker a guy into a bet.