We know that older blades had their center of gravity biased toward the heel since that's the common miss for better players. My understanding is that this came from a longer hosel and/or higher heel. When Webb Simpson won the US Open using 680's, that got me thinking, do they also have a heel-biased COG? For me, the 680 is one of the best examples of a modern blade, so I'd think the COG would be in the center of the face.