UFC 166: With win over Junior dos Santos, Cain Velasquez will join Randy Couture, Brock Lesnar and Tim Sylvia in Heavyweight history

The best evah?

Being Ultimate Fighting Championship (UFC) Heavyweight champion makes a mixed martial arts (MMA) fighter, for all intents and purposes, the baddest man on the planet. It also makes him a target for the other heavyweights who want what he has.

Such is the case for UFC Heavyweight Champion Cain Velasquez when he collides with Junior dos Santos later tonight (Sat., Oct. 19, 2013) at UFC 166 from Toyota Center in Houston, Texas , in their much anticipated trilogy match. Velasquez will look to become only the fourth UFC heavyweight king to successfully defend his belt twice.

Two times? That's right, in almost 20 years of existence, only three out of the 15 champions have defended the belt twice. Randy Couture, Tim Sylvia and Brock Lesnar are the three men to accomplish this rare feat.

When Velasquez reclaimed the 265-pound strap after his dominant unanimous decision performance over dos Santos at UFC 155, he joined Couture and Sylvia as the only fighters who have won the UFC heavyweight championship multiple times. It was also the first heavyweight title fight to go five rounds since the UFC 68 clash between Couture and Sylvia and only the seventh time it's ever happened in the division since the institution of rounds.

When the American Kickboxing Academy (AKA)-trained fighter steps into the Octagon this evening, it will mark his fifth title fight appearance, placing him in a three-way tie with Frank Mir and Andrei Arlovski for second all time behind Couture and Sylvia's nine title-fight appearances.

One of the most interesting stats about the history of UFC heavyweight title fights is the lack of ability for fighters who have lost their belt to reclaim it from the man who beat them. The obvious reason for that being because of a title-fight rematch not occurring. When Velasquez avenged dos Santos loss last December, he accompanied Sylvia as the only other heavyweight to do so in the division's history.

Sylvia, of course, lost his belt to Arlovski at UFC 51, before winning it back at UFC 61.

Sylvia and Arlovski, coincidentally, are the only other UFC heavyweight trilogy, with Arlovski losing the last two of their battles. The only other rematch in UFC title fight history is Couture defeating Pedro Rizzo a second time, via technical knockout at UFC 34, after the Hall of Fame-inductee had defeated him via unanimous decision at UFC 31.

Tonight's main event will probably not be the last time that we see dos Santos and Velasquez fight each other. With both fighters still relatively young in their respective MMA careers and clearly a notch above the rest of the division, they should almost certainly become the only two UFC heavyweights to face off for a fourth time inside the Octagon.

Should Velasquez be victorious, he will tie the defense record at two, and could very well be on his way to becoming the first UFC heavyweight champion to defend the title three times, or maybe more. If he loses, dos Santos becomes the third man to avenge a title-fight loss and it's back to the drawing board as far as defenses go.

Most UFC title fight appearances:

1. Randy Couture/Tim Sylvia: 9 (including interim title appearances for Sylvia)
2. Frank Mir/Andrei Arlovski: 5 (including interim title appearances for both)
3. Cain Velasquez/Brock Lesnar/Kevin Randleman: 4
4. Junior dos Santos/Maurice Smith: 3

Most UFC title fight wins:

1. Randy Couture: 6
2. Tim Sylvia: 5
3. Andrei Arlovski/Brock Lesnar: 3 (including interim title fight for Arlovski)
4. Frank Mir/Junior dos Santos: 2 (including interim title fight for Mir)

Fighters to win UFC heavyweight title more than once:

1. Randy Couture: 3X
2. Tim Sylvia: 2X
3. Cain Velasquez: 2X

Most UFC heavweight title defenses

1. Randy Couture/Brock Lesnar/Tim Sylvia: 2

UFC heavyweight title fights to go all five rounds

1. Kevin Randleman def. Pete Williams UFC 23
2. Kevin Randleman def. Pedro Rizzo UFC 26
3. Randy Couture def. Pedro Rizzo UFC 31
4. Tim Sylvia def. Andrei Arlovski UFC 61
5. Tim Sylvia def. Jeff Monson UFC 65
6. Randy Couture def. Tim Sylvia UFC 68
7. Cain Velasquez def. Junior dos Santos UFC 155

Will Velasquez make history later tonight or will dos Santos make some of his own?

Remember that MMAmania.com will provide LIVE round-by-round, blow-by-blow coverage of the entire UFC 166 card this evening below, starting with the Facebook "Prelims," which are scheduled to begin at 6 p.m. ET, right on through the FOX Sports 1-televised under card bouts at 8 p.m. ET and then main card PPV action, which is slated to begin at 10 p.m. ET.