I’ve never fully understood what it means when people talk about showing on the AA/A circuit, or the B circuit. All I’m aware of is that the AA/A circuit are bigger, and more professional shows. Can anyone shed some light on this for me?
It’s the USEF rating of the show. AA shows are the “premier” shows - those are the top rated shows. The A shows are the “national” shows. The B shows are “regional” shows but still rated by the USEF.
https://www.usef.org/documents/hunterJumper/showstandards.pdf
Then most places have various local circuits that are not USEF rated. These vary wildly as far as how they are run, what the level of competition is, etc.
When we talk about the “circuit”, we’re generally talking about the yearly calendar of shows recognized by the United States Equestrian Federation (and the United States Hunter Jumper Association). Riders who compete “on the circuit” are moving from show to show throughout the year, in an attempt to accumulate points or prize money won towards year-end awards in divisions specific to their and their horse’s ability levels. In the Fall, the “circuit” finishes with the championship “indoor” shows, then a new circuit begins for the new show calendar year (starting each December).
“Circuit” can also refer to a group of shows (usually recognized) that run consecutively for weeks or months. For instance, there are “winter circuits” in FL, MS and CA that run 6-10 weeks each.
Riders/trainers/owners can choose to participate in an entire circuit, or just part of one, though settling down to a showgrounds for the whole thing is often done.
The More "A"s after the name, the more money you’re gonna be throwing at a chance to get a $.30 ribbon 
I’ve been told by a show manager, the ONLY difference between A, B and C shows is the money offered in the prize list. Of course the “premier” shows would have the most money offered…
Just to add a bit to the confusion, though, some places use the phrase “The B Circuit” to mean local shows run under USEF rules, but NOT actual B-rated shows. So when you talked about “The A Circuit” and “The B Circuit” you were talking about rated versus unrated shows.
I’ve lived in two areas that did this. The B Circuit shows were well attended and well run with nice jumps and good judges and solid competition, but they weren’t rated shows.
I remember them being rated by amount of prize money by division and historical number of entries. And of course, the more prize money, the more entries attracted. And it was done by division. So (taking it to my experience and out of H/J terminology) a show could be rated A for Saddlebreds and rated B for Morgans etc.
Plus, some divisions are always rated one thing, even if they’re at a higher rated show. For example, Children’s Hunters and Adult Ammy’s are C rated divisions, even if they’re being held at a AA show.
