In Nick's book, it says to install cheek plates "just slightly aft of center". Does this mean that the center of the cheek plate (mine are 6" wide) should be just aft of center,or that the leading edge of the cheek plates should be just aft of center?

Also, does center mean the center of the boat or the center of the cockpit?

Thanks. (Don't know if it matters or not, but I'm building a 14' Great Auk.)