Counter Canter on a Straight Line

Today Karen taught us a nice exercise for counter canter on a straight line. Begin from collected trot from the short side, for example on the right rein starting from C. Using the corner (between C and M in this example), begin a small amount of counter flexion left (bringing the shoulder in helps to insure the "correct" lead to get started) and ride straight ahead. Weight your left stirrup, counter flex left, and cue for left canter at B. Keeping the counter canter aids, at P make a twenty meter counter canter half circle to V, then ride straight ahead to make another twenty meter counter canter half circle at C. Again, ride straight ahead down the long side and make a transition to collected trot at B.
For the left rein, beginning from C ride straight down the long side, counter flex to the right and weight your right stirrup and at S cue for right canter, make a twenty meter counter canter half circle left from V to P, ride straight ahead down the long side, then another counter canter half circle left at C, then straight ahead and make a down trans to collected trot at S.