UFC 166: 3 things you need to know

UFC 166: Velasquez vs. Dos Santos 3 kicks off on pay per view at 10 p.m. on Saturday, with online preliminaries at 6:15 and the Fox Sports 1 preliminaries at 8.

The card is highlighted by the highly anticipated third heavyweight title fight between champion Cain Velasquez and challenger Junior dos Santos and includes several intriguing undercard bouts.

Here are three things to know, plus the full card, heading into Saturday's event:

The Rubber Match
This is the third fight between Velasquez and dos Santos, with the heavyweights having split the first two contests.

After winning the UFC heavyweight title from Brock Lesnar in late 2010, Velasquez entered  the octagon over a year later for his first defense, against Junior dos Santos. Undefeated at 9-0 heading in, Velasquez was caught early by the punching power of the Brazilian, getting knocked out in just 1:04.

Now the champion, dos Santos had one successful defense before Velasquez got his rematch, having dispatched of Antonio Silva in a de facto title eliminator fight. Just over a year after their initial meeting, Velasquez picks dos Santos apart for a five-round unanimous decision victory, earning his title back and evening up the series.

Velasquez once again dispatched of Silva, while dos Santos took out Mark Hunt to earn another title fight and a third match in the series.

If you care for a refresher, UFC has posted both previous fights for free via YouTube:

With two great fights in the books, Velasquez and dos Santos have a chance to join a strong group of MMA trilogies:

The Tale of the Tape
The following graphics come courtesy of Sherdog:

The two fighters are very evenly matched when it comes to experience and track record, which makes sense considering they've each won a fight against each other.

Dos Santos is the more dangerous striker, as evidenced by his early knockout of Velasquez in the first meeting. He's more accurate and has heavier hands (he's finished 12 fights  by knockout to Velasquez' 10 with an earlier average stoppage time), though Velasquez striking defense is just as good as dos Santos.

When the fight gets beyond striking is where Velasquez excels, and he took down dos Santos 11 times with 111 strikes landed in their second encounter. Velasquez is relentless in trying to force the fight to the ground and punishing opponents when he gets down there, and not even a strong dos Santos takedown defense can hold up against his attack.

This all makes it pretty clear that a fight on the feet gives an edge to dos Santos, where a fight on the ground will keep the belt around Velasquez' waist.

Where do we go from here?
Here is a full list of Velasquez' opponents since the Lesnar fight in October 2010: Junior dos Santos, Antonio Silva. That's it.

Velasquez and dos Santos' trilogy has dominated the top of a thin heavyweight division for two full years now, but surprisingly the contenders aren't lined up champing at the bit.

Instead, the next challenger for the title is likely Fabricio Werdum, who is 17-5 and has won three straight fights. However, Roy Nelson has said he expects a title fight next if he beats Daniel Cormier in one of Saturday's uppercard fights. Cormier, meanwhile, is heading to light heavyweight and targeting Jon Jones with a win.

It's possible that if the champion needs a long lay off, the winner of UFC 168's Josh Barnett vs. Travis Browne fight could get a shot, as well.

The rest of the card
Main card:

Fox Sports 1 prelims:

Facebook/YouTube prelims: