Anderson Silva or Chael Sonnen should be the first names that come to mind. That is a natural leap to make, but neither are the correct response.
If Silva were to drop the belt to Sonnen on Saturday night it would do nothing to his legacy. He has dominated for a long time and written his chapter in the history of MMA. A loss does nothing to diminish what he has done.
For Sonnen, another loss to Silva is nothing that ruins his career. And like Silva he is on the backside of his career. Sonnen has made his name from the trash talk of this rivalry and playing Silva's greatest nemesis. Win or lose.
As you continue down the card you see names like Tito Ortiz and Forrest Griffin. The trilogy fights means very little to anyone. Outside of the fight being Ortiz's final one the interest level is relatively low.
Cung Le is a 40-year-old who recently lost. Expectations are not as high as they once were. Patrick Cote is a late replacement and a middle-tier middleweight. Both Demian Maia and Dong Hyun Kim would be losing to a top talent so a loss would do minimal damage.
So, who has the most to lose? For my money it is Chad Mendes. Why?
He is the biggest favorite on the card and expected to return to the top of the featherweight division. A loss to Cody McKenzie would be devastating.
Suffering a loss to the former "The Ultimate Fighter" cast member would send Mendes spiraling down the featherweight ladder.
As the overwhelming favorite it would send shockwaves through the division if McKenzie were able to upset Money at UFC 148. When a massive favorite gets upset it takes a long time to recover both in the good graces of the UFC and in the fan's eyes.
It is not a stretch to say that Mendes is not one of the division's most exciting fighters to the casual fans. In spite of his obvious skills, it took awhile before he got his shot at the championship belt; And suffering a KO loss to Aldo immediately sent him backwards.
The UFC has no problems giving exciting fighters, or at least those who are perceived to be exciting, another crack at the championship. But if you suffer a brutal defeat and are not the most eye-pleasing fighter you have to string together another list of dominating performances.
Ask Jon Fitch.
It took Fitch eight consecutive victories to earn his shot at GSP. After a lopsided decision loss to the champion he was still considered one of the best 170-pounders in the world, but another five wins in the division still did not earn him another crack at the champion.
Two consecutive losses would put Mendes at the back of the pack with a long way to go before putting himself back in title contention—something he will desperately want to avoid.
Mendes should be able to defeat McKenzie, but as we have seen in MMA, anything is possible. Mendes can not afford the possible to happen.