Small Fish In A Bigger Pond

The Little Secret of the WEC Merger

In December 2010, Anthony Pettis leapt out of the WEC cage and landed a kick to Benson Henderson’s face. The spectacular “Showtime Kick” highlighted the waning moments of the final fight of the World Extreme Cage fighting organization. The folding of the bantamweight, featherweight, and lightweight fighters into the UFV came with a bang. While Zuffa had owned the WEC for years prior, and management had already implemented operational practices from the UFC, most fans may not know about one key difference that the WEC fighters faced.

The biggest questions at the time of the merger focused on whether smaller fighters would be enough of a draw to warrant airtime on MMA’s biggest stage. Stars such as Urijah Faber and Jose Aldo certainly could put on a show and had strong followings, and the WEC’s highlight reel boasted amazing fight-ending knockouts and submissions, all taking place in the vivid, electric blue WEC cage. Despite having fewer marquis stars, the greater threat to the smaller weight classes was the new, full-size UFC Octagon. In the WEC, fighters competed in a 25-foot diameter Octagon. At 30-feet across, the full-size UFC Octagon may not seem quite so huge at only 20% bigger diameter, but that translates into a cavernous 44% increase in Octagon area. That makes the cage in the WEC pretty tight quarters by comparison.

Let’s settle this once and for all. What has been the effect of adding smaller weight classes to the UFC.


Finish rates in the UFC are inherently a scrutinized statistic. People want to see fights finished, and the UFC wants exciting ends to fights for the fans and highlights for future promos. However, the most important variable affecting finish rates is the size of the fighters.

It’s pretty clear that the bigger the fighter, the more fights they finish. This is true across the board in the UFC. Another definite trend is that the mix of finishes changes from predominantly submissions to mostly knockouts with increasing size. This is due to the physics of muscles and striking, not the heart of the fighters. Accounting for the fact that smaller fighters finish less often, did moving into a larger cage have any effect on how these fighters perform?

Fortunately, we have a great way to test this hypothesis. Before the WEC-UFC merger, several weight classes operated in parallel, which meant two different cage sizes. Furthermore, the UFC still uses the smaller cage for The Ultimate Fighter show and TUF Finale events, meaning we can look at finish rates for different events. Let’s look at those three scenarios, all while controlling for fighter size.

The results show that finish rates are higher in smaller cages, and this is true for all the weight classes where we have good data. The spike for the bantamweights is most likely due to the small sample size of bantamweight fighters competing in TUF Finale events, because there have only been 15 of those since the merger. But even more conclusively, we see higher finish rates in all weight classes in the small cage of the WEC and TUF events, including the lightweights and welterweights, who have been around longer and have more total fights to examine.

When put into a smaller cage, even larger UFC weight classes (welterweight and above) finish more fights. They also throw more than 20% more strikes per minute than when they are in the full-size Octagon. Same rules, same division, same matchmaker… just more action. The idea is confirmed: smaller cages result in more finishes.


Smaller fighters fighting in bigger cages could have spelled disaster for the WEC divisions, were it not for the upside to being small: endurance. Most fans know that they can expect two featherweights to maintain a frenzied pace of fighting far more intense than larger fighters, and they can do so for longer periods of time. Like two squirrels wrestling for a nut, they don’t seem to get tired, no matter how wild the fight gets. Look at the new flyweight division as evidence that two little guys can get after it for 15 minutes straight and be exciting the entire time, even without a spectacular KO finish.

How that translates into metrics is clear. Smaller weight classes (flyweight through lightweight) average 16% more significant strikes landed per minute than the larger half of the UFC (welterweights through heavyweights). They do this despite having much longer fights on average due to their lower finish rates. Smaller fighters can push the pace faster and longer than their heavier peers.


A fighter’s career can live or die by the bonus. It can be a windfall payday for a broke fighter, and, perhaps more importantly, it can cement the legacy of their value in the eyes of management. For the moment, let’s use the three Fight Night Bonuses (KO, Submission, and Fight of the Night) as a rough indicator of how exciting fighters are, and let’s look at how the weight classes stack up.

Although it’s still early, it certainly looks like the lighter divisions are holding their own. The flyweight sample size is quite small, and it may return to normal with time. And no one can match the devastating knockouts that occur in the heavyweight division. But overall, bantamweight and featherweight fighters have been putting on more bonus-worthy performances than the UFC’s middleweight and light heavyweight divisions. The lightweights actually earn bonuses at three times the rate of middleweights. Notably, the middleweights—who have the largest weight difference to the next class up— also have some of the lowest activity pace and bonus metrics of all. Perhaps there’s another insight for the MMA masses—cutting too much weight really does hurt performance.


• Size matters in fighting, and larger fighters finish more often.

• The size of the cage also matters— smaller cages lead to more finishes, but are used less often.

• The lighter WEC weight classes hold their own in the larger UFC Octagon.

• Smaller fighters have a much higher striking pace than larger fighters.

• The lighter weight classes have been holding their own by putting on bonus-worthy fights.

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