Reducer scribed to fit door jamb? Please Help!!
 

Or should I say Door jamb scribed to fit reducer? I understand undercutting the door jamb to allow the floor underneath. But what do I do to the door jamb for an overlap reducer? Do I scribe the door jamb to allow the reducer underneath? If I use the jamb saw all the way across the door jamb there will be a gap above the narrow end of the reduser. Or does the reducer butt up against the door jamb?

Butt to the jamb. No need to go under....