henry crun,
Position's A/B/C/D mark the position of the left wingtip in a barrel-roll to the right; A/B/C/D would mark the position of the right wingtip in a barrel-roll to the left assuming the image was mirrored I guess...
John Farley,
IMO Henry's diagram is perfect - so far as it goes What he misses is that you pass through A in a recovery from a preceding dive.
You mean you're pulling out of the dive after finishing the barrel-roll?