Re: Nike Jersey Sizing
If it helps; I am an XXL in soccer jerseys, my Reebok #80 jersey is an XL and is a little big; my #56 is XXL and is good for going over hoodies.
My Nike #99 is XL and is slightly smaller than the Reebok XL.
One of the bigger differences is the armpit area; if you shrug your shoulders in the Nike, the whole thing lifts up. Would have been terrible in the 6-10 season!