You gotta go with the hothand here and that's the dude who's undefeated in Stungun.
Let's not gloss over that Diaz's last two wins came against a seriously one dimensional striker in Davis who's best days are behind him and a guy in Markham, who was nearly ten pounds overweight and basically cut before the fight. Kym's got tonnes of refinement to his game and won't get lobbed into a brawl with the slapstriker in Diaz. His overall fighting is evolving at a great pace and from the Brown fight onward has progressively gotten more and more technical with glorious balance and timing and is just too solid for Diaz I believe.
MY MMA RANKINGS
HW Velasquez Cigano Werdum Cormier Bigfoot Barnett Mir Browne
LHW Jones Machida Evans Hendo Davis Goose Teixeira Shogun Mousasi Bader
MW ASilva Rockhold Belfort Weidman Jacare Okami Kennedy Consta Belcher Boetsch
WW GSP Hendricks Condit MacDonald Diaz Maia Fitch Kampmann Ellenberger Pyle
LW Bendo Alvarez Maynard Melendez Thomson J.Miller Diaz Pettis Chandler Grant dos Anjos
FW Aldo Mendes Curran Lamas Frankie Zombie
BW Cruz Barao Fernandes Faber Moraes