What prompted this the first time years ago was the people buying McMansions for a half a million bucks complained that ma and Pa Kettle who have lived in their house since WW II are paying less taxes when they both have the same number of bedrooms. Of course 5 of the Kettles 6 bedrooms are unused except when the children/grandchildren come home for Christmas, whereas the McMansionites have 4 spawn in school where most of the taxes go. They are also the ones telling the schools they need more of every thing that doesn't help educate the kids. The local school board paid some consultant $500,000 to investigate ways to make the high school look less like a school.
I stay away from the whole thing to avoid arrest.
Also, traditionally houses were reassessed when they changed hands either by sale or inheritance.