Degreeing Cam by Measuring Overlap @ Lifters

I helped a local guy some time back. He/ I had asked here, about his specific cam, where it should "be." The opinions were to wind it ahead. Turns out the sprockets were off (retarded) from where the grinder said it should be. So between the recommended advance, and correcting the retard in either the cam or the drive, we wound that thing ahead something like 6 or 8 degrees. "Night and day" difference in this case

In his case he had a drive set with several keyways in the crank gear, so it would go a ways................