I didn't feel like riding today. So I decided to try free jumping Riv instead. It took a couple tries for him to figure out what I wanted, but he got very good about going to the left. To the right..... not so much.
Note that I say he's "good about going", not that he's actually good AT going. He managed to jump without hitting the rail maybe once or twice out of a dozen or so jumps. Next time, I'll set up trot poles before to get him set up well and picking up his feet.
And some video:
And River being dumb: