UFC 166 fight card: Daniel Cormier vs. Roy Nelson fight preview

UFC 166 is set to pop off this Saturday night (Oct. 19, 2013) from Toyota Center in Houston, Texas, and it features a blockbuster co-main event in the form of Daniel Cormier vs. Roy Nelson.

The two heavyweights are on different career trajectories right now, with Cormier defeating Frank Mir in his Ultimate Fighting Championship (UFC) debut last April. Although it was deemed a lackluster victory, the win kept Cormier's undefeated record in mixed martial arts (MMA) intact.

"DC" will look to extend his win streak against heavy hitter Nelson, who most recently dropped a decision to underdog Stipe Miocic at UFC 161. But all is not lost as Nelson knocked out three straight foes prior to the Miocic loss. He has the power to put away any fighter in the world, but he's struggled against elite martial artists who implement high-movement gameplans.

Cormier will be the decided favorite against "Big Country," but it's never fair to count Nelson out. Although Nelson has becoming a bit one-dimensional as of late, that one dimension has a penchant for putting talented fighters to sleep. Can Nelson do the same to the sport's No. 2-ranked heavyweight this weekend?

Let's take a look at the keys to victory for Daniel Cormier vs. Roy Nelson:

Daniel Cormier

Record: 12-0 overall, 1-0 UFC

Key Wins: Josh Barnett (Strikeforce: Barnett vs. Cormier), Antonio Silva (Strikeforce: Barnett vs. Kharitonov)

Key Losses: None

Keys to Victory: Cormier is a former Olympic wrestler who has taken the MMA world by storm, compiling a spotless record while obtaining the Strikeforce World Heavyweight Grand Prix Championship as his great accomplishment.

His initial performance in UFC was underwhelming, but "DC" attributed that to a case of the very real Octagon jitters. Look for him to put on a better show in Houston.

To beat the experienced Nelson, Cormier will look to score takedowns from the opening bell and control where the fight goes. Cormier can take away Nelson's main strength of striking by using his world-class wrestling. Nelson has shown that top-flight grapplers can trouble him, and Cormier could have the best mat skills in the heavyweight division.

Cormier also has big power in his hands, but it would be a bit foolish to risk being clipped by a big overhand right just to prove that he can stand with "Big Country." Besides, Nelson has an iron chin -- exhibited in his brutal UFC 117 loss to Junior dos Santos -- so it's going to be nearly impossible to put him away with strikes.

Submissions aren't really a big part of Cormier's game at this point in his career, but he does have a brown belt in Brazilian jiu-jitsu. It has yet to be truly displayed or tested, but if and when this fight hits the ground, Cormier will be at a disadvantage. Two out of Cormier's three submission wins were due to punches. On the other hand, black belt Nelson has put five opponents away with a tapout.

Cormier will focus on transitioning his striking into effective takedowns, negating "Big Country's" massive knockout power by pushing him up against the cage. It may not be flashy, but there's a great chance that it will be effective.

Roy Nelson

Record: 19-8 overall, 6-4 UFC

Key Wins: Cheick Kongo (UFC 159), Stefan Struve (UFC Fight Night 21)

Key Losses: Stipe Miocic (UFC 161), Fabricio Werdum (UFC 143), Frank Mir (UFC 130), Junior dos Santos (UFC 117)

Keys to Victory: Nelson has fought a long list of recognizable heavyweights throughout his lengthy MMA career. Problem is, he's lost to most of the truly elite fighters that he's squared off with. He's been able to knockout mid-tier opposition, but he's still waiting for a truly defining win to propel him to the next level.

Cormier would definitely be that win, but Nelson will have to put forth the best showing of his life to get it. Nelson knows that he'll be faced with multiple takedowns attempts -- it's just a matter of if he can stop them or not. The odds are he can't; at least not for the entire bout.

"Big Country's" going to have to hope he can find a home for his trademark right hand. Nelson has only been knocked out once. He won't be scared to throw mitts with reckless abandon in Houston, but a clear opening will be tough to come by.

When the fight hits the mat, Nelson will have the edge in pure jiu-jitsu. He's talented and experienced on the ground, despite not having submitted a single opponent since 2006. Nelson has never tapped out, but it would be a surprise to see Cormier go for a submission in the first place.

Nelson will also have to be in peak condition (for him, at least). He's shown a negative tendency to gas out in big fights. Recently, however, he's been seen looking quite svelte. That will help him against a tough wrestler like Cormier.

This fight will absolutely hinge on Nelson's takedown defense. If he plays into Cormier's hands, he's going to get ground out and lose a clear-cut unanimous decision.

Bottom Line from Houston: The bottom line here is this fight will pretty much singlehandedly prove if Nelson can hack it as a top-level heavyweight or not.

Cormier has repeatedly stated that he is making the cut down to light heavyweight for an attempt at Jon Jones' belt after this fight and it's Nelson's job to spoil those plans this weekend.

If Cormier has already begun the weight cut, his strength may take a hit. He's never been the biggest or strongest heavyweight, but he makes up for it in technique. His extensive wrestling background should dictate where this fight takes place.

Nelson has the opportunity to shock the world as a big underdog. He appears to be in the best shape of his UFC career, and that should pay dividends against Cormier. Whether it will translate into success in terms of fighting off "DC's" takedowns remains to be seen. Nelson should be able to maintain a higher pace than he has in the past, so his haymakers might have more power on them later on in the fight.

He'll have to catch Cormier with a big one if he wants to emerge victorious. A submission or decision win remains an unlikely outcome for "Big Country" in Houston.

This fight is also going to show us if Cormier's hype is justified or not. With a win, he'll likely call out Jones for a title fight. An upset loss will cause a fall down the line of UFC heavyweight contenders.

Daniel Cormier and Roy Nelson will take to the Octagon to prove they are among the best mixed martial artists in the world. Do you give a big edge to "DC," or can Nelson pull off the monumental upset?