This is way better than the head proportion thing I learned from... That always made faces look stretched and weird. I just assumed I was doing it wrong. They had eyes being centered on that halfway mark, rather than the brow lining up to it. It all makes sense now.
Well the eyes are technically usually still centered from the very top of the head to the chin, but when starting with a sphere, then it is the brow line that is centered on the halfway mark. Glad this helps!