SamuelRSmith on 07 January 2015
My guess is that he has formulas with various weights and inputs to pump out the numbers, which may work across platforms (ie, if he knows one region typically over-or-under represents a particular console, so if you have numbers for console X in a region, you can make some assumptions about console Y).
He (I guess) modified those weights to get the new PS4 number, and thus also got a new X1 number.
