Motion Comfort Ratio was developed by Boat Designer Ted Brewer. The formula predicts the speed of the upward and downward motion of the boat as it encounters waves and swells. The faster the motion the more uncomfortable the passengers. Thus, the formula predicts the overall comfort of a boat when it is underway.
A more complete explanation is here: https://wavetrain.net/2011/10/15/crunching-numbers-brewer-comfort-ratio/