In a recent article, Bill Heimann did an excellent job of delineating the difference between high quality and high level dancing.
Most dancers aspire to be in the group that is so recognized.
Bill discussed the criteria he uses in evaluating how well or how poorly a dancer performs. Adaptability - better dancers can adapt to a situation that represents a logical extrapolation of known material without having to be taught or walked through. Precision - better dancers make precise formations and adopt precise facing directions. Ability to recognize the unright - better dancers realize when something does not make sense, when a formation cannot be correct, and therefore a mistake has been made. Ability to recover - when good dancers make a mistake, or find themselves in a situation they do not understand, they can adjust so as to keep the square moving.