Cam degreeing help me understand!

I haven’t read through all of this, but this last page is a reminder of why I always get the 9-way adjustable timing sets if they’re available for what I’m working on.
No matter how screwed up the cam or keyways are, you can always get within about a degree of the target......without having to drill anything or buy other parts.

For proper degreeing, the correct type of follower for the cam(flat/roller) must be used.