[mikeJ]

Value Raising Range: 8x/88/99/JJ/KK; Possibly AK/KQ/KJ/AA

How often is he bluffing? Pretty much never.

Ok, so how many 8x hands are in his range? Well, you beat 87/86/85/8T/8A. I think a lot of players will fold all of those hands to a raise, so I would say the 8x hands should be heavily discounted from his range.

How likely is he to be overvaluing AK/KQ/KJ/AA? I don't think it's very likely that he's shoving w/ 1 pair of kings, that's a pretty bad play that I don't think a lot of players will do, so unless you have a read that he's terrible and/or overplays hands, I would discount these hands from his range as well.

His line fits 88/99/JJ pretty well, KK is somewhat less likely because of the flatcall preflop.

You're getting ~4 to 1. So does he show up w/ a worse hand 20% of the time? I don't think he does.