I have a book on Small Circle Jiu-jitsu and I think the stuff is interesting in a way. From what I gleaned from reading the book (it was written by the founder, Wally Jay) it is a little more judo like with its throws, but has some low single leg takedowns. Lots of standing wrist locks and non-bjj type arm locks. If you've ever studied traditional Japanese jiu-jitsu, seeing something like a straight arm lock with the legs is rare, mostly guys turn their backs to the opponent and make a frame over the arm. A lot of stuff like that.
There is some mat work, but not a whole lot from what I saw. The vast majority of the mat work in the book revolved around going for a low single leg, controlling the leg and stepping over the opponent to turn them onto their chest, and hooking their leg from the inside and pinning the instep against your abdomen to put pressure on the knee. He had this one takedown where it was a low single leg into a reverse Indian deathlock. No way in hell it'd ever work, maybe against someone who was in a coma or something.
Other than that, what makes "small circle jiu-jitsu" small circle is the motion that you apply to do a choke or lock. Rather than just bend a joint the wrong way, they will do a lock that way while driving the blade of their forearm into the tricep tendon to make it more painful.
Any BJJ practicioner eventually starts using this "small circle" motion in grappling though. You twist your wrist to emphasize the blade of the forearm for chokes and locks. It was just revolutionary at the time because no one had grappled like that.
