Adam Morgan

The prisoner's dilemma of the UFC

Since the UFC’s debut in 1993, the sport has seen many changes in its rules both for entertainment purposes as well as a means to increase the level of protection for the fighters. In the early days of the UFC, fighters entered the octagon without gloves and would fight to the finish. A fight could only end through submission, knockout, a referee stoppage, or the classic throwing of the towel. Fighters today wear gloves and compete in fights that are typically three or five rounds that last five minutes each. Perhaps the most significant change was the introduction of weight classes. Now, fighters are matched against other fighters of similar and nearly identical weight.

Fights that are arranged by weight are drastically different than the early days of the sport. In its very first event, a 216 pound man was matched up against a 434 pound man. At the most recent UFC event, UFC 171, the greatest difference in weight between two fighters was 1.5 pounds and even this small difference resulted in a 20% purse penalty for the heavier fighter.

While there were many legitimate reasons for introducing weight classes, it has produced unintended consequences that affect the health of the fighters.

The day before a UFC fight, both fighters weigh in to ensure they are within the specified range for their weight class.

Let’s assume two fighters are competing in the welterweight division. Before the day of the fight, both fighters must weigh-in at or below 170 pounds. What’s important here for the fighters are the days leading up to the weigh-in along with the 24-hour period after the weigh-in before they enter the octagon to fight.

In the days leading up to the fight, the fighters begin the process of “cutting weight”. From a dietary standpoint, the fighters slowly reduce water intake to flush out their body. They also avoid carbs, fruits, sugars, salt, and starch. Combine this with hot baths and saunas and fighters can lose anywhere from 10-30 pounds in just five days.

Immediately after the weigh-in, fighters reverse the entire process. They start drinking water again, fill themselves with carbs, proteins, and fats, and add salt to everything they eat to help their body retain water. In just a 24-hour period, the fighters who weighed in at 170 pounds will walk out to fight that night weighing anywhere between 180-200 pounds.

The process is painful and damaging both physically and mentally. Why do they do this? It’s a classic case of the prisoner’s dilemma.

Prisonner's Dilemma

If competing fighters within a given weight class were to avoid cutting weight as shown above, both would be better off. The fighters would be of equal weight and wouldn’t suffer the damaging effects caused by cutting weight. So our 170 pound fighters in the welterweight division could maintain their original size which is closer to 190 pounds, avoid cutting weight, and fight in the middleweight division instead.

Here’s where the competitive defect comes into play. Rather than maintain a weight closer to 190 pounds, why not cut weight down to a lower weight class, gain all the weight back, and fight with a significant weight advantage over your opponent who has maintained a consistent weight? This possibility of a defector along with the competitive weight advantage it brings is exactly why fighters cut weight. Strategically, they’re better off cutting weight and collectively suffering the consequences than maintaining their weight and hoping their opponents do not defect.

I bring up this issue because people within the sport have expressed concern about the weight cutting process without a clear understanding as to why it’s happening. It’s dangerous to the fighters and even affects the quality of the sport. The fighters may gain most of their weight back before they fight, but the fighters cannot fully recover in a 24-hour timeframe. Competing at a world class level leads to fighters who fatigue much quicker than they would under normal circumstances.

As far as how to solve this issue, I can’t say for sure. I’m not aware of the logistics within the UFC to recommend a practical solution. Coordinating production crews, venue setup, and fighters from city to city is an intensive process and the weigh-ins may work around all of this.

However, assuming the fighters arrive on location a few days in advance, a longer weigh-in process could do some good and potentially solve the problem. Rather than a single weigh-in the day before a fight, several weigh-ins could take place over a few days. These weigh-ins could require a consistent weight each day which would essentially force fighters to maintain a normal weight. Having to maintain a consistent weight through multiple weigh-ins would eliminate the ability for fighters to flush their system out and regain such a large amount of weight in such short time.

Extend the weigh-in process and we could see fights with healthier and stronger fighters without the negative physical and mental effects of cutting weight.


Thanks to Logan Jones and Joey Morgan for reading drafts of this post.