I finally figured out IGN's review system. Most sites are reviewing at 10. They're at ten there, all the way up. Where can you go from there? Where? Nowhere...
So what IGN's review system does is have an unspoken feature to give it that extra push over the cliff, their system secretly goes to ELEVEN.
So with that knowledge suddenly the reviews like Jade Empire - 9.9, Jak II - 9.5, God of War - 9.8, Metal Gear Solid 3: Snake Eater - 9.6, and the many others previously thought to be outrageously high suddenly make total sense.