Only a small cluster of the world's top fighters can say they've gone years without tasting defeat.
UFC champs like Georges St-Pierre (welterweight), Jose Aldo (featherweight) and Benson Henderson (lightweight) each understand how sweet reigning supreme over a division for an extended period of time can feel.
But while "GSP," "Bendo" and "Scarface" surely have their respective divisions in check, only genuine wunderkinds like Anderson Silva and Jon Jones can demand respect in the debate of the world's best pound-for-pound fighter.
So if "The Spider" and "Bones" represent the world's top two pound-for-pound fighters, at least according to the UFC rankings, then which virtuoso truly controls the top spot?
Here's a look at why Jones has a decided advantage over Silva in the pound-for-pound debate.