This article is part of our MMA Barometer series.

Looking back on the history of the promotion, UFC 189 may have been the best event ever. After a forgettable preliminary card, Matt Brown got things started in the preliminary main event with a first-round submission of Tim Means following one of his devastating trademark elbows. From there, the night only got better as every fight on the main card was finished before it went to decision. Anybody who purchased this card definitely got their money's worth, as there were two finishes via flying knee, one submission and two TKOs via punches.

The night started off with a flying knee victory from Thomas Almeida against Brad Pickett, which was only to be one-upped in the third fight by Jeremy Stephens' flying knee followed by punches to finish Dennis Bermudez. This was followed by arguably the best title fight in UFC welterweight history, as champion Robbie Lawler retained his belt via TKO in the fifth round against Rory MacDonald. Lawler and MacDonald went back and forth on the feet for most of the fight, with each fighter almost knocking out the other in the early rounds. Lawler was out on his feet at the end of the third round and beginning of the fourth, but showed true championship grit to survive and ultimately get the finish in the fifth round. MacDonald showed he was a game opponent for the champion, and displayed championship toughness -- he was winning on all three judges' scorecards going into the fifth round. After the fight, it was discovered that MacDonald had both a fractured foot and a broken nose, making his performance even more impressive. The card was worth the buy based on this fight alone.

Of course, in the main event Conor McGregor lived up to his personal prediction and knocked out Chad Mendes in the second round. It was only fitting that one of the biggest UFC stars ever capped off possibly the best UFC card we have ever seen. Even though McGregor spent most of the fight on his back, he was able to get to his feet in the second round and take advantage of a gassed opponent by landing a straight left hand to knock down Mendes, which ultimately led to the TKO stoppage. McGregor is a huge star and his performance to protect his title shot against Jose Aldo was a perfect way to end such an epic card.

UFC 189 was second to only maybe UFC 100 in anticipation from fans and experts alike, and it delivered. It is not often that a card that is anticipated to be historically great actually lives up to the expectations. Not only was it a great fight card, but it will certainly help to boost the popularity of both welterweight champion Robbie Lawler and interim featherweight champion Conor McGregor. Each fighter has become must-see TV and they each played a major role in making UFC 189 the best UFC event that has ever taken place.
Now, let's move on to the current risers and fallers in the sport.

Rising

Stephen Thompson
Stephen Thompson has cemented himself in the top ten of the UFC welterweight division with his spinning hook kick knockout of Jake Ellenberger at The Ultimate Fighter 21 Finale. Thompson, now the No. 9-ranked UFC welterweight, is on a five-fight winning streak following his victory over Ellenberger, who was ranked No. 9 at the time. Thompson is the owner of a perfect 57-0 record in kickboxing, and his exceptional striking pedigree translates well to the Octagon. This was exemplified in his fight against Ellenberger, where he first used a spinning hook kick to knock him down, and then, once Ellenberger recovered, used a second spinning hook kick to finish the fight in the first round. This comes as no surprise considering Wonderboy's kickboxing experience, but it is the other skills he showed that will make Thompson a major player in the UFC welterweight division in the near future. Since his unanimous decision loss to Matt Brown in 2012, Thompson has greatly improved his wrestling and grappling ability while training alongside UFC middleweight champion (and elite wrestler) Chris Weidman under coaches Matt Serra and Renzo Gracie. During his fight with Brown, Thompson had difficulty defending takedowns. However, during his five-fight win streak, Thompson has displayed improved takedown defense and even secured takedowns of his own. During the TUF 21 Finale, Thompson was able to secure a takedown against Ellenberger, which was unexpected because of Ellenberger's Division II wrestling credentials. As Thompson continues to improve his ground game to pair with his elite kickboxing, he will pose major problems for any welterweight in the UFC. Look for "Wonderboy" to continue to improve as a mixed martial artist and continue his win streak in the fourth quarter of 2015.
Next fight: TBA

Tony Ferguson
Tony Ferguson boasts a staggering six-fight win streak in the UFC lightweight division. Including his victory in the championship of TUF 13: Team Lesnar vs. Team dos Santos, Ferguson is 9-1 in the UFC. His only loss came via unanimous decision to Michael Johnson (No. 5-ranked UFC lightweight), who was the second replacement for original opponent Dennis Hallman. "El Cucuy" possesses a potent mixture of standup power, vicious ground and pound, and effective submissions. During his six-fight win streak, Ferguson has three wins via submission. In his most recent fight, at UFC Fight Night: Mir vs. Duffee, Ferguson displayed his killer instinct with a brutal display of ground and pound after hurting Josh Thompson on the feet. Thompson, a mixed martial arts veteran and former Strikeforce lightweight champion, was able to survive the punishment and survived the fight en route to a unanimous decision loss. Ferguson passed a huge test in his bout against Thompson, a top-ten UFC lightweight, but he can expect even more challenging fights as he climbs the ladder in the UFC lightweight division. It will be interesting to see how Ferguson responds as he faces elite fighters in his division, but the future looks bright for "El Cucuy."
Next Fight: TBA

Ovince St. Preux
Former Tennessee Volunteer football player Ovince St. Preux is one of the hottest commodities in the UFC light heavyweight division. He has won seven of his last eight fights, and finished six of those wins. St. Preux possesses a lot of power in the stand-up game, which he combines with solid wrestling skills. Many of his fights have been finished by KO/TKO on the feet, but St. Preux possesses so much power in his kicks that he forced Ryan Jimmo to verbally submit because of a broken arm caused by blocking one of them. St. Preux's biggest win was a 34-second knockout of future Hall of Famer and former champion Mauricio "Shogun" Rua, when St. Preux was a later replacement for the main event in Rua's home country of Brazil. St. Preux recently defeated Patrick Cummins via first round knockout, but he will face a huge step up in competition in his next fight against Glover Teixeira. If St. Preux is able to emerge victorious, expect him to either fight for the title or be in a title eliminator against a top-five opponent.
Next Fight: Glover Teixeira, UFC Fight Night: Teixeira vs. St. Preux (August 8th, 2015)

Check Status

Rory MacDonald
MacDonald's welterweight title fight with Robbie Lawler at UFC 189 was perhaps the best title fight in UFC welterweight history. MacDonald and Lawler fought on the feet for most of the fight and MacDonald almost finished Lawler in the late third and early fourth rounds before ultimately losing via TKO in the fifth. MacDonald has won eight of his last ten fights, with is only two losses coming to Lawler. However, after his gutsy performance while fighting for the title, the UFC probably won't hesitate to give him another shot at Lawler after he wins a few non-title fights. MacDonald is undoubtedly one of the most skilled mixed martial artists in the world and his fighting style is truly beautiful. He mixes a fluid striking game with his black belt in Brazilian Jiu-Jitsu, so MacDonald is dangerous anywhere the fight takes place. MacDonald may have lost the fight to Lawler, but both fighters showed true championship grit and MacDonald is definitely worthy of another title shot. MacDonald is still only 26 years old, and will most likely be a UFC champion before the conclusion of his career. MacDonald's mentor, George St. Pierre, also lost his first title fight, but his career turned out alright, so hopefully MacDonald can follow St. Pierre's blueprint.
Next Fight: TBA

Falling

Holly Holm
It is not often that an undefeated fighter finds herself on the falling list. Holm entered the UFC as a hot commodity with championship aspirations, and is a decorated boxing champion with an undefeated mixed martial arts record. Before joining the UFC, Holm won all but one of her fights by KO/TKO, and even added a head kick with knockout power to go with her boxing. Many fans expected Holm to contend for Ronda Rousey's women's bantamweight title, but her performance in the Octagon has been underwhelming thus far considering the expectations when she entered the promotion. This is not to say Holm has not been successful, as she has won both her bouts in the UFC. However, it's worth pointing out that her stock may be falling a little bit because of how good she looked before entering the promotion. Winning her two fights by decision against opponents who are not in the top ten does not give much reason to believe Holm can contend with the elite fighters in the division like Cat Zingano, Miesha Tate, or Ronda Rousey. However, Holm is in great position to improve her MMA game at Jackson-Winkeljohn MMA under legendary trainer Greg Jackson. Holm has already gained good skills as a mixed martial artist by adding more diverse strikes to her arsenal and developing good takedown defense (100 percent in UFC). Expect a step up in competition for Holm's next fight, which will shed light on her ability to hang with elite fighters in the division.
Next Fight: TBA

Lyoto Machida
Machida has lost two fights in a row for only the second time in his mixed martial arts career, and he was finished in both fights. These two fights were against quality competition in No. 1-ranked UFC middleweight Luke Rockhold and No. 3-ranked UFC middleweight Yoel Romero, but this is the type of competition Machida has become expected to defeat over the course of his career. Machida seems to be slipping away from being a title contender in the middleweight division. It appears that he does not hold the size advantage he expected to have at middleweight, and it may be time for the karate master to return to the light heavyweight division where he is a former champion. At light heavyweight, Machida will be able to rely on a speed advantage which is effective when coupled with his counter-attacking karate style. It would also allow Machida to cut almost no weight, which is always an advantage as fighters get older (he's 37 years old). It's become apparent that Machida could use a change of scenery after losing two fights in a row at middleweight.
Next Fight: TBA

Antonio Silva
Antonio Silva has lost three of his last four fights, with the other fight being a draw against Mark Hunt. After his fight with Hunt, Silva tested positive for elevated testosterone levels. "Bigfoot" is possibly the only fighter in the UFC who actually needs testosterone replacement therapy (TRT), which has been banned from competition. He suffers from acromegaly, which is a form of gigantism, and Silva has used testosterone to combat the condition. Since TRT has been banned, Silva tested positive for elevated levels when he looked great against Hunt, and he didn't look like the Bigfoot of old in his recent losses. His last two fights have been brutal knockout losses to Andrei Arlovski and Frank Mir. With the new rules in place, it might be best for Silva to retire if he is unable to halt his losing on August 1 in his home country of Brazil against Soa Palelei.
Next Fight: Soa Palelei, UFC 190: Rousey vs. Correia (August 1, 2015)