Originally Posted by canadiancow

In that specific case, the earn rate of B and A are the same, so it's irrelevant.

In the general case... I don't even have any data since they switched to 1A. You'd need to find a paid J itinerary with a single-cabin connection. Historically, it definitely posted as whatever it was booked into (either 100% or 125%), but 1A may have changed that.

Originally Posted by Nitehawk

One thing worth mentioning is that B and A both earn at the same rate regardless (125%).

There are other potential cases...I've found that business lowest often books economy only segments in M, and that the segments in M only post as M (100%).

Edit: now I need to check my records for flights post 1A in business lowest. I apparently didn't fly any bookings that meet that criteria.