There has been far more heat than light surrounding the current controversy over whether a transgender (male to female) fighter should be allowed to compete in mixed martial arts in the women’s division.
This article on The Verge said that opponents of Ms. Fox competition “are not supported by the current science”, citing the fact that the International Olympic Committee allows transgender athletes to compete under certain conditions – set number of years post-surgery, hormonal therapy.
Since mixed martial arts is not an Olympic sport whatever science on which this decision was based most likely did not include any studies involving mixed martial arts. I say most likely because although I asked on my other (personal blog), where I write about sports a lot for citations of this supposedly voluminous scientific literature no one provided me any relevant references and I did not uncover any searching the National Library of Medicine database. A few people did send me references to articles on hormonal therapy but none of these even discussed the issue of sports participation. Their focus instead was on the possible side effects, e.g. cancer or other ill effects, of people with various hormone regimens.
The most reasoned discussion on this topic I have read is on Dr. Rosi Sexton’s blog, and I agree with her three main points:
- There is not much at all in the way of data documenting whether or not Ms. Fox has an advantage competing in martial arts. Expert opinion is split on this issue.
- No one has a right to compete in mixed martial arts. There are all kinds of qualifications – you have to be a certain weight and gender to compete in a division. You can’t be pregnant.
- Mixed martial arts are different than say, canoeing, because you are trying to do bodily harm to your opponent. Unlike in many sports, a Type I error – rejecting a true null hypothesis – is likely to cause harm to others.
Read her blog. It’s good. Personally, I want to address a couple of other points. On twitter, Shelly Summers made the comment that it was difficult to dispute that Fallon Fox (or any transgender fighter) does not have an advantage unless it is spelled out exactly what her advantage is supposed to be. Now here I’m on firmer ground at least because we can couch this in terms of an equation. Logistic regression would be best, with win or loss as the dependent variable. The question then is what are the independent variables. This might seem a straightforward question but it’s not. Let’s start with what should be obvious.
1. Different sports have different requirements for success. Males don’t seem to have an advantage in equestrian – the sport is mixed gender in the Olympics. We have separate shooting events for men and women, but I don’t know why. Winning the marathon requires more endurance. Winning a gold medal in weight-lifting requires more strength. Women tend to do better in long-distance swimming. Men are better at football. Height is an advantage in some sports (basketball, volleyball) and not in others. I could go on, but you get the point, I hope, which is that you cannot generalize about “sports”.
2. Even in the sports like football, baseball and basketball where millions of dollars are spent on data analysis, the predictions are far from perfect.
3. There are several variables that predict athletic success, including in mixed martial arts.
I know a lot more about judo than mixed martial arts specifically, but there is some overlap, so let’s look at what you certainly need:
- Physical strength. While technique will beat strength, if other things are equal, the match goes to the person with more strength. It’s like using steroids – it doesn’t guarantee you the win, but it gives you an edge. People have argued that the hormonal levels of transgender females are no different than those born female. A more relevant test would be measures of physical strength. Given that two people of the same weight engaged in the same strength and conditioning program would there be a difference in measures of strength like the maximum weight in the bench press, dead lift , the maximum number of repetitions at a given weight, recovery after a given rest period, etc.? I don’t know. It might also be hard to assess this if people knew they were being studied because either person might consciously or subconsciously lift less and affect the results. This is why researchers favor double-blind studies where neither those collecting the data nor those giving it know if they are in the experimental or control group. The only way I see you could do this though, is through deception, e.g., telling both parties you were assessing the effect of a specific hormone regimen. Regardless, as far as I know these type of data are not available from well-controlled (or really, any) studies.
- Endurance. A judo competition is several matches of four minutes each, usually with a rest period of 10- 60 minutes in between. Mixed martial arts matches are either three or five five-minute rounds, with short rests in between. An indirect measure might be something like lung capacity, but a more direct measure would include things like resting heart rate immediately after each round. Physiological measures are not my specialization, but I cannot imagine any way in which direct measures would not be preferable to indirect ones. Again, this is an area where I am not aware of any research, certainly not for MMA specifically.
- Reach. I can guarantee this from having fought for years – and having won a world championships, I fought at a pretty high level – competitors who have a much longer reach have an advantage.
- Psychological factors. If you have watched many combat sports at all, you have seen those matches where someone should not have won and yet they did. This is something every top athlete has, that absolute refusal to lose.
- Speed. If you can beat your opponent to the punch every time (figuratively as well as literally) you will win.
Have there been studies establishing transgender female mixed martial artists and other female mixed martial artists on these characteristics? I’m almost certain not. If we don’t have any evidence that Ms. Fox does NOT have an advantage, it would make sense to agree with Dr. Sexton that it is best to err on the side of the safety of the other women in the division and disallow her competition.
One thing did immediately strike me when I heard about this story that made me say — wait a minute. Fallon Fox is 37 years old. How many professional competitors in women’s mixed martial arts are 37 or older ? I looked up the women’s rankings in the Fight Matrix for the 145 and 135 lb divisions. I added Ms. Fox into the mix, and to be fair, I also added Peggy Morgan, the woman who would have been her opponent in her next bout, except she has announced she refuses to fight Ms. Fox. While MMA Junkie lists Ms. Fox age as 43, other sources list it as 37, so I used the lower age. To give one more data point, I added Marina Shafir who just won her fight tonight and is the same division as Ms. Fox. Since Marina is only 24, I calculated the results with and without her. Still significant.
Here is the age distribution for those 30 women.
There is exactly one woman older than Fallon Fox among those competitors – Hitomi Akano. Ms. Akano lost her last two fights . ** NOTE CORRECTED ON 3/27/2013 see comment below.
The average age of the other 29 fighters was 29.21. Using a z-test with this as the population value and the population standard deviation of 3.9 gives a z-value of 1.99. If we were conducting a one-tailed test of the hypothesis that Fox is significantly older (based on an assumption that a transgender female would have an advantage and be competitive at a later age) we would reject the null hypothesis as the critical value of a one-tailed test is 1.64. However, if we were to use the more rigorous two-tailed test and say our alternate hypothesis is that being transgender could be an advantage or disadvantage, we’d still accept the null hypothesis as the z-value is greater than 1.96
At most we can say there is slight evidence for an advantage, and that based on a small amount of data.
We can note that in this sample, as Ms. Akano has not won a fight since she was 36, there is exactly one person in here with a winning record after age 36, and that is Ms Fox. There are nine fighters in this sample that have winning record of 100%. The other eight fighters range in age from 24 to 33 with an average age of 28.9 years.
What we can say from this admittedly small sample of data is that Ms. Fox appears to be winning decisively at an age that is significantly older than the average female competitor in or near her weight division. At least as far as the age at which she is successful in competition, Ms. Fox DOES appear to be significantly different than a sample of mixed martial arts fighters who were born female. Could this be because she is more determined, trains harder, wants it more or just has an amazing coaching team? Yes, it could. Could it be because we only have a small sample which could be non-representative of women mixed martial arts fighters? Yes, it could. I’d be happy to do a large, well-controlled study with lots of variables, but it turns out that I have to get back to doing the analyses for which people pay me money.
Anyone else is welcome to find their own data, list their sources and post it or publish it wherever they like. Please give a link in the comments if you do. What I did was use the data that was available to me and actually looked at female mixed martial artists and performance. What I did not do was consider data on hormones, law, a hypothesized set of data that somebody must have had somewhere before making a policy and not someone’s opinion on what people should or should not do in their private lives.