I think Biscuit probably was trained to do this a long time ago but his original trainer was harsh
and his methods were harsh. I think Biscuit was pushed hard in the arena and it has taken a long time to get him comfortable in the arena!
My former horse had a little training on side passing but he wasn't great at it simply from not being asked to do it often. I took lessons and that is what we worked on. We worked on side pass, turning on the forehand and hindquarters. When I took him to CakeMom he could side pass and turn on the forehand and hindquarters like a champ.
Biscuit will yield on the ground and always has...he just wouldn't when you were mounted. I was shocked today when I was able to get him to do it. It wasn't perfect but I will keep after it. LOL He can be such a snot. Next time I get on him and ask for a left side pass he is liable to have a meltdown like he used to. Hahahahahaha
I have a video on my blog with very exaggerated hand/leg cues to get Red to side pass...to go right, I lifted up the right rein, kept left rein straight, pressed with the left leg to get him to move right. Woot!!! And move right he did.