Why No UFC Heavyweight Champion Has Defended the Belt More Than Twice

The UFC heavyweight title is considered the crown jewel of combat sports.  On Saturday night at UFC 160, Cain Velasquez will begin his second reign as heavyweight king, as he looks to defend his belt vs. Antonio “Bigfoot” Silva.

If Velasquez beats Silva, he will only be one defense shy of the heavyweight division record.  That’s right—no champion has ever made it to three.  Only Randy Couture, Tim Sylvia and Brock Lesnar have defended the title twice.  

It may be easier to win the heavyweight strap than it is to defend it.  Perhaps it’s because the harder you try to hold onto something, the easier it is for it to slip through your fingers.  Or it just comes down to numbers and some risk management.

Let’s take a look at the numbers and try to solve the mystery of why no UFC heavyweight champion has defended the belt more than twice.

Since Mark Coleman defeated Dan Severn to become the first UFC heavyweight champion in 1997, there have been 13 different champions in the promotion's history, along with four interim champions.  Velasquez, Couture and Sylvia are the only three to have won the belt more than once.

In the 23 UFC heavyweight title fights that have taken place under the Zuffa banner, almost half of them haven't made it past the second round.  Eleven contests have ended within the first two rounds, for an average of 47 percent.

The old "force equals mass times acceleration" formula comes to mind.  When the largest athletes connect with a clean punch with only a four-ounce glove or land an uninterrupted kick, someone usually goes down in a hurry.  

Blunt-force trauma, so to speak.

Some highly skilled grappling technicians have participated in these 23 contests, but only five of them have won by submission.  Lesnar was the last one to do so, submitting Shane Carwin via side-triangle choke at UFC 116. 

What about the fourth and fifth rounds, aka the “championship” rounds?  Only five of these title contests have gone the distance, for a meager 21 percent—the most recent being Cain Velasquez vs. Junior dos Santos at UFC 156.  

Prior to that bout, you’d have to go back to UFC 68, when Couture won by unanimous decision over Sylvia.  The only time a heavyweight championship fight ended in the fifth round was at UFC 39, when Ricco Rodriguez defeated Couture by submission.

Most of these behemoths just don't have a big enough gas tank to tread the deep waters late in fights.  They are built to end these battles at a violent and fast pace.  

The average title-fight time for the heavies is 10 minutes and 47 seconds—just into the third round.  If a fight doesn’t make it to a decision, the average time is seven minutes and 47 seconds—about midway into the second round.

Something or someone has to give before the third round is over, and it’s usually in the form of a knockout.  Five-round decisions are a rarity; there were 87 pay-per-views in between the last two of them.

The primary reason that no fighter has successfully defended the UFC heavyweight championship more than twice comes down to the inherent risk of fighting in the division.  

If he makes one mistake, a fighter may become someone’s "Knockout of the Night” bonus.  If he squeaks past the third round, he has a good chance of listening to Bruce Buffer announce the decision rather than the referee waking him up.

As a minus-800 favorite on Bovada, Velasquez may defeat Silva, but the odds are not in his favor that he'll defend the title another time.

Will Velasquez be the first to defend the UFC heavyweight title more than twice?  Let Bleacher Report know in the comments below.

Michael Stets is a Featured Columnist for Bleacher Report.