Just a sort of off topic question; bay and brown are caused by the same thing correct? Black horse with agouti?
If so, then is it correct to say that browns are just very dark versions of bay, where the black has not been restricted to such an extreme degree?
Brown and bay do act differently, it is not just a matter of one being darker than the other. They both do restrict black, but in different ways, not just to a lesser or higher degree.