A POST ABOUT POSTING
Perhaps this is redundant. And, it's possible I heard this somewhere and it just now registered... or it might be my very own insight.

Having never taken many formal equitation lessons, and being a wearer of the Western costume, the concept of posting to the trot is rather foreign to me. Posting to the correct diagonal? Big head scratcher. Many people have tried to explain it. The least confusing explanation I've heard was to "rise with the outside leg when it is fully extended".

Well, that's a lot of thinkity-think to be doing during a ride.

I did recall that during one PNH clinic, we "rehearsed" riding in circles without our horses on the ground for the canter to learn how to pick up leads and what those meant. I decided to take that approach with trotting and "trotted" a circle in my kitchen. I "rose" with my outside leg when I picked it up.

But... what was my other leg doing?

It was the one carrying my weight. It was firmly planted. I was pivoting on it.

AHA.

A circle is just a very wide pivot. If the circle is narrowed to a smaller and smaller diameter, eventually it turns into a spin. You—or the horse—will pivot on the INSIDE leg. For a horse, if he is moving FORWARD (this is very important because he has two legs per side), his FRONT leg is his pivot leg for the turns. (If we're talking reining spins, that's pivoting on the hind foot which doesn't apply here.)

It makes absolute sense to POST TO THE PIVOT, does it not?

Especially if you're riding with Fluidity, which means you are actively riding, not just sitting like a sack of potatoes. When you're actively riding, your feet are pedaling in harmony with him. You're trotting (or walking or cantering) in your body. When you do this, the posting occurs almost naturally.

I played with the concepts in my kitchen. PLEASE TRY THIS AT HOME! :-) You'll see what I saw—that it is uncomfortable to rise when the outside leg is planted because it causes you to want to turn in that direction. Try it.

I "trotted" (in slo-mo) a circle going to the left. My left foot is the pivot. Going left, left foot pivots, rise when he plants his left front hoof which you'll sense if you're pedaling and actively riding with him. When I rose with the pivoting foot, it felt fine.

When I tried to rise with the outside leg planted, it felt "off".

Left circle, left leg. Right circle, right leg.

OK, NOW the concept of "inside leg" makes sense.

But I like mine better. POST TO THE PIVOT. Think I'll go give it a whirl.