Actually, IMAC is precision aerobatics and turnaround. You enter the box once and you exit the box at the end.

To watch a skilled IMAC pilot will from a distance not look any different than a skilled Pattern(AMA) pilot.

The judging downgrades on IMAC are actually more severe than Pattern. IMAC is 1 pt for 10 degrees variation and Pattern is 1 pt for 15 degrees variation. Both score for wind corrected manuevers, both score the center manuevers from a center point directly in front of pilot, and both have a box with penalties for going outside the box, although Pattern is tougher on this one.

Having competed in both, the Unknowns are the true difference. As well as the planes. I love both of them so try to have a realistic and unbiased opinion of them.

Pattern planes are inherently smoother, more graceful. The big IMAC planes can be flown this way, but more snaps in a sequence makes it seem more harsh. There is some difference in the naming of the manuevers, but over all the same stuff. See me signature.

Won't go into what I consider the really down sides as trying to be positive here and they are argued plenty on other threads.

All of this is to say am glad there is a place for both. Practicing for both disciplines also helps to keep me fresh and not burnt out per se.

Ed