Balance – Weather or Lee helm
If both the “C of E” and the “C of LR” are aligned vertically, then the boat will sail in a straight line, with the rudder in the straight ahead position.
If the “C of E” is aft of the “C of LR” then the boat has weather helm. The boat would turn itself into the wind if left alone.
If the “C of E” is forward of the “C of LR” then the boat has lee helm. The boat would turn itself away from the wind if left alone.
No boat performs well with lee helm, as the combined hydrodynamics of the keel and rudder are not making the water flow in the correct curve. Further, it is a dangerous and disconcerting experience to sail a boat with this configuration. Lee helm can happen to any boat if the headsail is too much bigger than the main when the main is reefed, or not up at all.