As expected, Conor McGregor outclassed Dennis Siver in the main event of UFC Fight Night Boston. While Siver was able to land quite a few leg kicks throughout the fight, he did so while his head was getting blasted by an endless barrage of straight punches, uppercuts, and kicks. By the end of the first round, Siver could barely stay standing, and by the time McGregor knocked him down in the second round, Siver’s will to fight was completely broken.
That victory sets up the expected title fight between McGregor and current featherweight champion Jose Aldo, and a round of speculation about McGregor’s chances of defeating the champion. There are already odds out on the fight; Aldo opened as a mild favorite at -140, with McGregor the underdog at even money. That line has quickly moved as the price on Aldo has climbed to -165 with McGregor at +125.
Even with all the hype surrounding McGregor, it’s surprising to see Aldo as only a slight to moderate favorite to win. Here are the historical closing lines on previous Aldo fights in the UFC, per Best Fight Odds:
- UFC 179: Jose Aldo -200, Chad Mendes +185
- UFC 169: Jose Aldo -750, Ricardo Lamas +600
- UFC 163: Jose Aldo -875, Chan Sung Jung +685
- UFC 156: Jose Aldo -175, Frankie Edgar +165
- UFC 142: Jose Aldo -230, Chad Mendes +210
- UFC 136: Jose Aldo -355, Kenny Florian +320
- UFC 129: Jose Aldo -500, Mark Hominick +435
Against the two opponents considered Aldo’s toughest challengers in the featherweight division – Chad Mendes and Frankie Edgar – the price on Aldo ranged from -175 to -230. This implies that not only is McGregor a serious threat to defeat Aldo, but that he’s more of a threat than either Mendes or Edgar. But is this implication justified? Should McGregor truly be considered Aldo’s toughest challenger so far? Or, to take the discussion even further – does McGregor deserve to be the favorite in this fight?
As readers of this blog know, I like to tackle questions like this from a statistical standpoint. On the surface, the Fight Metric numbers look pretty overwhelming in McGregor’s favor:
- Significant Strikes Landed per Minute: McGregor 5.72, Aldo 3.29
- Significant Strikes Absorbed per Minute: McGregor 2.98, Aldo 1.94
- Takedowns Landed per 15 Minutes: McGregor 2.60, Aldo 0.93
- Takedown Accuracy: McGregor 83%, Aldo 72%
- Takedown Defense: McGregor 100%, Aldo 91%
McGregor has Aldo beat in every category except significant strikes absorbed, and McGregor’s margin of +2.74 strikes per minute is far better than Aldo’s margin of +1.35. McGregor also attempts and lands takedowns more often, suggesting that a fight between him and Aldo wouldn’t go well for the champion.
Of course, you’re probably screaming that the above numbers don’t adjust for strength of opposition, and that’s the category in which Aldo trounces McGregor. This is subjective, but this is how I personally rank the quality of each of Aldo and McGregor’s respective UFC opponents, at the time of each fight:
- Chad Mendes (Aldo)
- Frankie Edgar (Aldo)
- Kenny Florian (Aldo)
- Ricardo Lamas (Aldo)
- Chan Sung Jung (Aldo)
- Dustin Poirier (McGregor)
- Max Holloway (McGregor)
- Dennis Siver (McGregor)
- Mark Hominick (Aldo)
- Diego Brandao (McGregor)
- Marcus Brimage (McGregor)
In my humble opinion, every UFC opponent Aldo has fought was better than every UFC opponent McGregor has fought, with the exception of Mark Hominick (and I might be selling Hominick short in the above list). It could easily be argued that Aldo’s +1.35 significant strike margin and 91% takedown defense statistics are more impressive against the level of competition he’s faced than McGregor’s respective statistics.
Another thing I’ve been doing recently is regressing Fight Metric statistics to the mean. Generally speaking, statistics that are regressed to the mean are better indicators of “true” ability than statistics that are not regressed. When I regress Aldo and McGregor’s Fight Metric statistics, the gap between them narrows considerably:
REGRESSED FIGHT METRIC STATISTICS (FOR UFC FIGHTS ONLY)
- Significant Strike Margin: McGregor +1.15, Aldo +0.60
- Takedowns Margin per 15 Minutes: McGregor +0.62, Aldo +0.49
Now, there are a number of things the statistics don’t take into account. Along with the quality of competition, the statistics don’t mention anything about the quality of strikes landed (quite good for both fighters) or the skill set of their respective opponents (Aldo has faced tough wrestlers while McGregor has battled mid-level strikers).
From a scouting perspective, the idea of a striking match developing between Aldo and McGregor makes me very excited, because it should be a great test of each fighter’s skill set. McGregor is a master of controlling distance, keeping his opponent at the end of his punches and kicks, and moving in such a way that he can deliver each strike with great force while leaving his opponent unable to effectively counter. Aldo is one of the best boxers in the sport, a fighter with extremely fast hands, clean technique, and very tight, technical defense. It’s very difficult for opponents to hit Aldo cleanly, and if they stay out of boxing range, they’re likely to eat a steady diet of brutal leg kicks.
As talented as McGregor is (and he does have legitimate world-class striking talent for MMA), there are two key factors leading me to conclude that the betting lines are giving him too much credit. The first is striking defense, a statistical category that has very good predictive ability compared to other categories. McGregor has consistently dished out far more punishment than he’s received, but it’s worth noting that he took 32 significant strikes in less than seven minutes against Siver, was hit 10 times in under two minutes against Poirier, and was hit 12 times in 67 seconds against Brimage. Sure, McGregor won all of those fights handily, but these numbers suggest that he is not particularly hard to hit. Aldo should be able to capitalize on striking opportunities in a way that fighters like Poirier were unable to.
The other factor is the level of competition, as mentioned before. It’s one thing to style on the Dennis Sivers of the world, but winning convincingly against guys like Mendes and Edgar – or even guys like Lamas – is another matter.
While I don’t have all the information I need quite yet, early indications from my statistical model suggest that the “true” price on Aldo should be something like -300. That effectively puts McGregor below Edgar and Mendes and above Aldo’s other challengers in terms of chances of winning. There’s no question in my mind that McGregor is a serious challenger who will test Aldo in ways he hasn’t been tested yet, but his chances of actually defeating Aldo probably aren’t quite as good as the current market price would suggest.