I've watched David Fitz put up regular 500+ AMA patterns with a pretty much normal weight Ringmaster with either a Veco 19BB (my airplane) or his own with a BB tuned Max .19. It must be flown quickly with constant speed which dictates high RPM and low pitch props which won't slow down appreciably in maneuvers. The CG, as with most stunters, should be as aft as allows good stability and controllable pitch rates...most flapless ships will be happiest around 15% MAC and probably shouldn't go aft of 20% as you'll lose feedback in the controls and find it hard to stop corners reliably. Plan on flying pretty quick lap times, somewhere in the mid four seconds or so. It sounds fast but it's a tiny airplane and its not like trying to fly a Super Snorter .75 powered 750 square inch behemoth. It's perfectly doable.
The important thing to remember, however, is to not try to pull out upright out of the inverted down intersection of your square vertical eights when the engine flames out like David did twice with my Ringmaster. When the fast revving low pitch prop stops sucking the Ringmaster turns into your grandpa's Ringmaster and it wil NOT return to upright flight without post flight reconstruction. David was a gentleman and fixed it both times.
Oh, and a last important thing that others have mentioned. Reduced elevator travel and slow controls are the ticket to flying good patterns. The stock, short plywood horn is a no, no. Get one of those long nylon ones and plan on the furthest hole out and something less than that at the bellcrank end. Use an adjustable spacing handle to control the sensitivity to suit the pilot. Don't try to trim a stable but responsive airplane to suit your desired handle response by adding weight to the nose or tail. Adjust the sensitivity with handle line spacing. Adding nose weight is not the way to go unless the airplane is unstable in the glide. Again, CG ~15%MAC should be right in the ball park for good AMA patterns if the other stuff is as suggested by others and above in this post.
Ted
P.S. Don't expect to win the Walker Cup with the airplane but, also, don't be afraid to fly it anywhere. You might not win but you'll impress people who say a Ringmaster can't fly decent tricks.
Ted