I’ve done quite a bit of homework on the green books, in fact you can purchase them for most courses from companies like Greenslopes, GolfLogix and StrakaLine (who I believe makes the PGA Tour books)–they are not cheap. I bought one for my home course, and the tournament legal ones have a precise resolution, like 3/8″ on paper = 5 feet of green, and no numeric slopes. They still make and distribute the old ones that are now non-conforming with greater resolution and numbers, so be careful if you buy one. The one that the CGA seems to be adding to their app appears to be the GolfLogix app version. I demo’ed the GolfLogix app a few months back. Like most yardage apps it has a regulation mode that you need to turn on and off for legal rounds. The regulation mode has the right detail, and the non-regulation mode has the feature that actually predicts your putt path–I tried it but it takes waaaay too long to use. Just like range finders we all need to make sure the proper mode is enabled in a tournament. Handicap trivia BTW, technically you are not allowed to even post a handicap score if you use the non-regulation features on a range finder or app like slope/wind/elevation etc., but between you and me if someone wants to score better and artificially deflate their handicap that’s OK with me!