The UFC heads to pay-per-view for the fifth time this year with Saturday’s UFC 173 event, its annual Memorial Day weekend event, which takes place at Las Vegas’ MGM Grand Garden Arena.

Headlining the “Sin City” fight card is bantamweight champion Renan Barao (32-1 MMA, 7-0 UFC), who will become the first UFC titleholder to put his or her gold on the line twice in 2014 when he battles “The Ultimate Fighter 14” runner-up T.J. Dillashaw (9-2 MMA 5-2 UFC).

Barao and Dillashaw were scheduled as the main event on short notice after the originally scheduled headliner of Chris Weidman vs. Lyoto Machida was pulled from the card. While the 135-pound title fight doesn’t have as much name value as its 185-pound counterpart, two of the world’s top athletes will still be in action.

Any time Barao prepares to compete, discussions about his one-of-a-kind winning and undefeated streaks are brought back to light. The 27-year-old has not suffered a loss in MMA competition since his professional debut in 2005, and he now goes for his fourth consecutive defense of the UFC bantamweight belt.

Barao’s streak is a common point of conversation in the sport, but he’s not the only highly credentialed athlete scheduled to step in the octagon at UFC 173. With that in mind, here are 75 pre-fight facts about Saturday’s event.

MAIN EVENT

Barao’s seven-fight UFC winning streak is the longest active streak in the bantamweight division. The Brazilian is undefeated (32 wins and one no-contest) in his past 33 bouts.

Barao owns the longest winning streak in UFC bantamweight history and is tied with Chris Weidman and Matt Brown for the second longest winning streak among active UFC fighters behind Jon Jones (11).

Barao’s 22-fight MMA winning streak is tied with Khabib Nurmagomedov for the longest streak among active UFC fighters.

Barao’s nine wins in UFC/WEC bantamweight competition are tied with Dominick Cruz for the second most in history behind Scott Jorgensen (10).

Barao’s six knockout/submission victories in UFC/WEC bantamweight competition are tied with Brian Bowles for the most in divisional history.

Barao has dominated opponents in the striking department throughout his Zuffa tenure; the Brazilian has never been out-struck in nine UFC/WEC fights.

Defense has a major role in the previous statistic, as Barao’s 67.8 percent significant strike defense rate is the third best in UFC bantamweight history behind Raphael Assuncao (72.3 percent) and Francisco Rivera (68.7 percent).

Barao’s 457 total strikes landed in UFC bantamweight competition are the fourth most ever behind Takeya Mizugaki (699), Urijah Faber (568) and Alex Caceres (537).

Barao’s defensive wrestling inside the UFC octagon has been nothing short of perfect. He’s stuffed 17 of 17 takedown attempts through seven fights. No fighter in UFC history has ever defended the first 20 takedowns attempted against him/her under the UFC banner.

Barao’s 95.2 percent takedown defense rate in UFC/WEC bantamweight competition is the best in history (minimum of five fights and 20 opponent attempts).

Barao’s submission of Michael McDonald at 3:57 of Round 4 at UFC on FUEL TV 7 marked the fifth latest submission in UFC history.

Barao is one of just three fighters in UFC history to earn a knockout stemming from a spinning back kick. He stopped Eddie Wineland with the technique at UFC 165. Barao is the only one of the three to finish a fight by landing a technique to the head.

Barao is one of just three UFC/WEC bantamweights to earn at least one “Fight of the Night,” “Knockout of the Night,” and “Submission of the Night” bonus (McDonald, Brad Pickett).

Dillashaw will become the 12th contestant from “The Ultimate Fighter” reality show to compete for a UFC championship. He joins Forrest Griffin, Rashad Evans, Nate Quarry, Patrick Cote, Josh Koscheck, Joe Stevenson, Diego Sanchez, Kenny Florian, Gray Maynard, Nate Diaz and John Dodson on the list. Of that group, only Griffin and Evans were successful in their bids to capture UFC gold. (Matt Serra also won a title after winning “TUF 4,” a special “comeback” season of the reality show.)

Dillashaw owns the most UFC victories of any bantamweight fighter from his season of “TUF.”

Dillashaw’s output of 4.84 strikes landed per minute is the highest rate in UFC bantamweight history. His 2.13 significant strikes absorbed per minute rate are the fourth least in 135-pound history.

Dillashaw’s +2.71 strike differential rate is the second largest margin for any fighter in UFC history behind heavyweight champion Cain Velasquez (+4.52).

Dillashaw’s average fight time of 8:28 is the third shortest in UFC bantamweight history behind John Albert (4:24) and Erik Perez (7:41).

Dillashaw’s 76 significant ground strikes landed against Walel Watson at UFC on FUEL TV 1 stand as the most ever in a single UFC bout.

CO-MAIN EVENT

Dan Henderson (30-11 MMA, 7-5 UFC), 43, is the oldest fighter in the light heavyweight division and the oldest active fighter on the UFC roster. He, of course, is also the oldest of the 24 fighters scheduled to compete on Saturday’s card.

Henderson became the second-oldest fighter to earn a knockout victory under the UFC banner when he stopped Mauricio Rua at UFC Fight Night 38 in March. Randy Couture, who finished Gabriel Gonzaga at UFC 74, is the oldest fighter (44) to score a knockout.

Henderson is the only fighter in UFC/PRIDE/Strikeforce history to hold two titles simultaneously, once reigning as the PRIDE welterweight (183-pound) and middleweight (205-pound) champion.

Henderson has beaten 10 former UFC/PRIDE/Strikeforce champions throughout his MMA career. All five of his UFC fights since returning the organization in 2011 have come against former 205-pound champions.

Henderson’s 23 victories in UFC/PRIDE/Strikeforce/WEC competition are the second most in the combined history of the four organizations behind Wanderlei Silva (27).

Henderson’s 13 knockout wins in UFC/PRIDE/Strikeforce/WEC history are tied with Anderson Silva for the fourth most in the combined history of the four organizations behind W. Silva (19), Mirko Filipovic (16) and Mauricio Rua (15).

Henderson has earned 18 total knockdowns in his UFC/PRIDE/Strikeforce career, which is tied with Filipovic and A. Silva for the second most in the combined history of the three promotions behind W. Silva (27).

Henderson’s 527 significant strikes landed in his PRIDE career are the third-most in the promotion’s history.

Henderson has landed 87.5 percent of his takedowns from the clinch in UFC/PRIDE/Strikeforce competition. His 48 takedowns landed in the three promotions are the fourth most ever by a fighter competing at 183 pounds or heavier.

Henderson’s 31 takedowns landed in his PRIDE career are the second most of any fighter in the now-defunct promotion’s history behind Kazushi Sakuraba (40).

Henderson has suffered 13 knockdowns in UFC/PRIDE/Strikeforce/WEC competition, which are the most of any fighter in the combined history of the four organizations.

Henderson’s average fight time of 15:24 as a UFC light heavyweight is the longest in company history.

Daniel Cormier (14-0 MMA, 3-0 UFC) is 4-0 in his career against fighters who once held or challenged for a UFC championship.

Cormier has never been taken down in his MMA career.

Cormier holds the record for the most victories (eight), knockouts (four) and significant strikes landed (305) in the history of the now-defunct Strikeforce heavyweight division.

Cormier has out-landed every UFC and Strikeforce opponent he’s faced. He out-lands his opponents by a nearly 3-1 ratio, landing 456 significant strikes to just 156 absorbed. His UFC/Strikeforce strike differential of +2.72 per minute is the sixth highest in the combined history of the two promotions (minimum of five fights).

REMAINING MAIN CARD

Robbie Lawler (22-10 MMA, 7-4 UFC) returns to the octagon just 69 days after his unanimous decision loss to welterweight champion Johny Hendricks at UFC 171 in March.

Lawler landed 150 significant strikes in that defeat, the third most ever in a UFC championship fight behind Hendricks’ 158 and Carlos Condit’s 151 in an interim title fight against Nick Diaz at UFC 143.

Lawler is 3-1 since making his return to the UFC for a second stint in February of this past year.

Lawler has a 13-1 knockdown ratio in UFC/PRIDE/Strikeforce/EliteXC competition.

Lawler lands 3.88 significant strikes per minute, the fourth highest rate among active welterweights (minimum of five fights).

Lawler’s 82.4 percent takedown accuracy (14 of 17) through his UFC career is more than double the current promotional average of 41 percent.

Lawler has been controlled on the ground for only 4.6 percent of his UFC welterweight cage time, the fifth smallest amount among active welterweights (minimum of five fights).

Jake Ellenberger’s (29-7 MMA, 8-3 UFC) eight knockdowns landed in UFC welterweight competition are tied for the second most in divisional history behind Thiago Alves (10).

Ellenberger’s five knockout victories are tied for the fifth most in UFC welterweight history.

Ellenberger has avoided 67 percent of his opponents’ combined significant strike attempts, the third highest striking defense rate in UFC welterweight history. He only absorbs 1.95 significant strikes per minute, the fourth best rate among active UFC welterweights.

Ellenberger has landed 55.9 percent of his takedown attempts, the second highest takedown accuracy among active UFC welterweights behind Rory MacDonald’s 57.6 percent rate (minimum of five fights and 20 attempts). Oppositely, Ellenberger’s defense has been spectacular. He’s stuffed 14 of 15 opponent attempts for a 93.3 percent takedown defense rate.

Takeya Mizugaki’s (19-7-2 MMA, 6-2 UFC) four-fight UFC winning streak is the third longest active streak in the bantamweight division behind Barao (seven) and Raphael Assuncao (six).

Mizugaki’s current four-fight winning streak is the longest of his 13-fight Zuffa career.

Mizugaki has been defeated by decision in four of his five of his UFC/WEC losses.

Mizugaki’s average fight time of 14:34 is the third longest in UFC/WEC bantamweight history. His total fight time of 3:09:20 in his UFC/WEC career is the longest of any bantamweight fighter in the combined history of the two promotions.

Mizugaki’s 660 significant strikes landed in UFC/WEC bantamweight competition are the second most in divisional history. His 1,092 total strikes are the most in bantamweight history.

Mizugaki’s 152 significant strikes landed against Nam Phan at UFC Fight Night 33 stand as the most ever in a UFC/WEC bantamweight fight.

Mizugaki and Phan combined for 252 significant strikes landed in their bout, a single-fight UFC/WEC bantamweight record.

Mizugaki’s 23 takedowns in UFC/WEC bantamweight competition are the fourth most in the division’s history. His 65.7 percent takedown accuracy is the highest in UFC/WEC bantamweight history.

Francisco Rivera (10-2 MMA, 3-1 UFC) is undefeated in four fights since making his return to the UFC for a second stint in May 2012.

Rivera has earned his past two UFC victories by knockout.

Rivera’s four knockdowns landed are tied for the second most in UFC bantamweight history behind Michael McDonald (five).

Rivera lands 4.59 significant strikes per minute, the second highest rate in UFC/WEC bantamweight history behind Dillashaw.

Jamie Varner (21-9-1 MMA, 3-4 UFC) has recorded just two wins in five fights since making his return to the UFC in May 2012.

Varner averages 4.8 takedowns landed per 15 minutes of fighting in his UFC career, the third highest rate in UFC lightweight history (minimum of five fights). His 37 takedowns landed in UFC/WEC competition are the sixth most in lightweight history.

Varner was on the losing end of the third largest statistical comeback in UFC history. “The Worm” out-landed Joe Lauzon by 38 significant strikes at UFC on FOX 4 before being submitted in the third round. The greatest single-fight comeback belongs to Anderson Silva, who came back from a deficit of 60 significant strikes to submit Chael Sonnen in the fifth round at UFC 117.

James Krause’s (20-5 MMA, 1-1 UFC) submission of Sam Stout at 4:47 of Round 3 at UFC 161 stands as the second latest submission ever in a three-round UFC lightweight fight. The finish came just one second short of Cole Miller’s record tap-out of Jorge Gurgel at 4:48 of Round 3 at UFC 86.

PRELIMINARY CARD

Michael Chiesa (10-1 MMA, 3-1 UFC) has earned his past six MMA wins by rear-naked-choke submission, four in the first round.

Chiesa is one of 13 fighters in UFC history to earn three or more rear-naked-choke submissions inside the octagon

Francisco Trinaldo (14-3 MMA, 4-2 UFC) is one of three fighters in UFC history to earn two arm-triangle-choke victories inside the octagon (Dan Severn and Eric Schafer). He’s the only fighter to do it in back-to-back fights, accomplishing the feat against Mike Rio at UFC on FX 8 and C.J. Keith at UFC on FX 7.

Opponents Tony Ferguson (14-3 MMA, 4-1 UFC) and Katsunori Kikuno (22-5-2 MMA, 1-0 UFC) have never suffered a knockout loss in a combined 46 professional MMA fights.

Ferguson became the 12th fighter in UFC history to earn a D’Arce/brabo choke submission win when he tapped out Mike Rio at UFC 166. The finish at 1:52 of Round 1 was the quickest of its kind in UFC history.

Chico Camus (14-4 MMA, 3-1 UFC) has earned his past six MMA victories by decision. That includes all three of his wins under the UFC banner.

Chris Holdsworth (5-0 MMA, 1-0 UFC) has earned all five of his career victories by submission. He has never gone past the second round in any of his combined amateur, “TUF” or professional fights.

Al Iaquinta’s (8-2-1 MMA, 3-1 UFC) three-fight UFC winning streak is tied for the fifth longest active winning streak in the lightweight division behind Khabib Nurmagomedov (six), T.J. Grant (five), Myles Jury (five) and Anthony Pettis (four).

Iaquinta has earned all three of his UFC victories by decision.

Mitch Clarke (10-2 MMA, 1-2 UFC) will compete in just his second MMA fight dating back to July 2012.

Anthony Njokuani (16-7 MMA, 3-3 UFC) has alternated wins and losses throughout his six-fight UFC career. The 34-year-old was victorious in his most recent octagon appearance.

Njokuani enters the event on the heels of a 399-day layoff. That’s his longest break from MMA competition dating back to his professional debut in May 2003.

Sam Sicilia (12-4 MMA, 2-3 UFC) is just 1-3 in his past four UFC appearances. He has been stopped inside the distance in two of those losses.

For the latest on UFC 173, stay tuned to the UFC Rumors section of the site.

FightMetric research analyst and live statistics producer Michael Carroll contributed to this story. Follow him on Twitter @MJCflipdascript.