Tom, that's really my question. Logically, one would think that more information has to be better, especially for the best putters in the world. But when you look at the level of detail provided in those books, I question whether any Tour pro or caddie but Bryson would even pretend to do the math necessary to calculate a line. And that's before you factor in green speeds and wind. It would be interesting to me if someone tested the hypothesis that the books are more of a validation or crutch than a difference-maker. Plus the "why not, everyone uses them" factor.