Then, your advertised duration is more like 51* and not 61*.....which is why I don't use the advertised.
Remember the old .480 lift 292 duration cams everybody made at one time years ago? All of them ranged from "around" 219 to "around" 230 "or so" , but their advertised durations were 292. This is why using the .050" figure is so much more accurate, IMO. It gives "the real" picture of "what" the cam "really is".
"Knowing" what the advertised duration is, is a nice thing to know, but it really serves no purpose other than to confuse, again, IMO.