If I use the table from the book and I enter a stroke from one these distances in the app I get different strokes gained numbers. In this case, the table says a 6 foot putt is average 1.34. So if I hole a 6 foot putt I assume you would win 0.34 strokes. But if I enter 6 foot in the app that I hole I gain 0.44 strokes (see attachment). Where does this difference com from.
The GM app computes both ‘Pro SG’ and ‘Scr SG’ (professional and scratch). You can toggle between them by pressing the text. You get a gain of 0.44 relative to a scratch golfer and 0.34 relative to a Pro golfer.