If you’ve ever watched any televised mixed martial arts (MMA), you will have seen something similar to the picture below, showing the ‘tale of the tape’ of two athletes about to engage each other with strikes and grappling movements to claim a win on their professional record and get paid.
You may also have noticed that sometimes, one or more of the measurements are highlighted, showing that one of the competitors has a larger measurement than their opponent, and in this case, Conor McGregor has a greater reach and height than Chad Mendes. Now why is this information provided and why is it highlighted? Well, the tale of the tape – much like many of the aspects of MMA presentation – is taken straight from boxing, and in the ‘sweet science’ being taller or having longer arms allows you more chance of hitting your opponent without being hit in return. So height and reach matters a lot in boxing!
But does it matter in MMA? I mean, suposedly, the taller person should still have more chance of hitting the shorter person with their fists, but what about kicks? What if the smaller person engages the taller one in a grapple or takedown, rendering their long limbs useless? What then? Does it still matter who needs the longer sleeves on their dress shirt? This is the question that my research has attempted to address over the last couple of years.
In order to do this, it was necessary to determine what could possibly be affected by a competitor having a greater height or reach. I decided that four key areas could be influenced by this:
- Long term success – if height/reach had an influence, then taller/longer participants would be distinguished from their less vertically blessed opponents in the divisional rankings.
- Who wins the bout – if height/reach had an influence, then most of the time the taller/longer participant would win
- How the bout ended – if height/reach had an influence, then taller/longer participants would get most of their wins via strikes
- The techniques used – if height/reach had an influence, then technique use would share some kind of relationship with these measurements
Now each of these areas are distinct, but play into each other in terms of what we would call ‘success’ in MMA.
Looking for an answer
The first study I conducted separated 474 international competitors into their divisions, recording their height and reach from the televised tales of the tape over one calendar year. I also used the height and reach measurements to calculate each competitor’s ‘ape index’, which is a measurement showing the scale of a person’s reach in comparison to their height. This particular measurement has been shown to be vital in basketball, so could it have relevance in MMA?
At the end of said year, each competitor’s divisional ranking according to Fightmatrix was recorded (I ignored the official UFC rankings, because everyone should). Each division was then split into either 3 or 4 ranking groups (RG) based on how many competitors were in each division and I then compared the mean height, reach and ape index of each group in each division in turn.
Jon Jones is usually the first thought when fans start discussing height and reach......
What these comparisons found was that there is no difference in any of the measurements, between any group in 8 of the 10 divisions included. In fact, the only differences found were in bantamweight where the highest ranked competitors were actually shorter (by 3-5cm) than the rest of the division, and at women’s strawweight where the middle ranks were about 5cm shorter than both the highest and the lowest ranked competitors! So it seems that being tall as a male bantamweight could actually be negative for your long term success, whilst it’s either a blessing or a curse as a female strawweight!
I also conducted correlation calculations on this data set between rank, height, reach and the ape index, finding that as rank increases, the fighters get shorter at lightheavyweight and lightweight, whilst the ape index also decreases at featherweight. Each of these correlations were moderate to small, showing not much of a genuine effect, and no other division had any correlation.
So, not looking so good for the height and reach so far! After this I decided to look at individual bouts to see if there was any effect of height or reach on who wins each bout. Here, I recorded the results of 278 international bouts along with the heights, reaches and ape indices of each of the competitors involved, and then calculated the differences between the winners and losers of each bout for each measurement.
Now the results of this one did suprise me a little! When looking at the full cohort, taller competitors were just as likely to lose due to strikes as they were to win by strikes. More importantly, when the losing competitor had a longer reach than their opponent, it was much more likely that they lost due to strikes rather than a decision. Equally, in the welterweight division, fighters with a longer reach had more chance of losing via submission than winning. Suggesting that having a longer reach is actually a disadvantage in MMA! In this study I also made use of a statistical method called Bayes factors, which allowed me to show evidence that when height and reach was advantageous, it was found to be anecdotal evidence only, whilst the disadvantageous results came out as very strong or decisive evidence.
....but what about 7'0" Stephan Struve being knocked out by several much shorter competitors?
So points 1-3 have had some evidence provided for, and it seems to be negative at this stage: if height/reach does have any influence, then it’s not a good one for the big’uns! So why is this? One suggestion could be that the grappling aspect of MMA has such a big influence that it mitigates any anthropometric dis/advantages, a result that has been mirrored in wrestling. Or, it could be that MMA is such a young sport that the competitors and coaches have not yet figured out how to use these size differences effectively and consistently. Or it could be that height and reach just does not matter in MMA, at least not to the point that people assume. So I decided to have a look at technique use in MMA and whether limb length had any influence here.
For this study I used the in bout data of 461 UFC competitors in one calendar year collected by Fight Metric (big thanks to Rami Genaur again for sorting this out!) to determine which techniques could distinguish between winners and losers in each bout, and which of these were correlated to differences between winners and losers in height, reach and ape index. First off, the ape index had absolutely no effect again, so I’m happy to disregard this measurement completely for the time being, unless other supporting evidence comes along. In terms of height and reach, there were statistically relevant regression equations found in heavyweight, welterweight, lightweight and featherweight, so let’s have a look at each of those in turn.
(Nb. The following section discusses % of variances. These represent how much of a difference in one measurement can be explained by another measurement. For example, if height can predict 10% of the variance in strikes, where Fighter A recorded 20 strikes, and Fighter B recorded 10 strikes, then 10% of the difference between them can be explained by the difference in their height.)
The difference between winners and losers in terms of significant strikes landed is related to the difference in height between winners and losers, as well as the difference in reach. Height differences were found to predict 30% of the variance in significant strikes landed, whilst reach differences predicted 41% of the variance, respectively. Equally, 33% of the variance in significant strikes attempted at heavyweight can be predicted by the difference in reach between winners and losers. These are real differences, with real consequences for performance, as significant strikes landed and attempted were also found to be distinguishing factors between winners and losers in this division, and something that can predict 30-41% of a performance in such a nuanced sport cannot be ignored. So let’s see about the other divisions.
In this division, the findings were a little less pronounced, with the differences in height predicting 8% of the variance in significant strikes attempted and 7% of the variance in significant distance strikes attempted. This shows that taller competitors at welterweight may possibly be attempting more strikes, and at a greater distance than their opponent, but simply attempting more strikes has been shown to not be of that much importance in deciding who wins in MMA. So, moving on.
Lightweight contained the only occasion where a grappling variable was found to be affected by height, with 6% of the variance in the number of successful guard passes between winners and losers could be predicted by height differences. However, if you look at the linked published version of this research and scroll to Figure 3a, there is a clear outlier in this data, which could potentially account for this variance. So I’m not about to hang my hat on this partiular finding when trying to predict who wins or loses in MMA.
In this division we’re back in a situation where height and reach does seem to have a real effect on effective striking. Differences in height between winners and losers was found to predict 13% of the variance in knock downs and 9% of the variance in distance knockdowns, respectively. Differences in reach were also found to predict 16% of the variance in knockdowns and 12% of the variance in distance knock downs. So in a similar vein to heavyweight, there could actually be something in the adage that size matters for featherweights.
So why does this not show in the previous studies looking at wins/losses or ranking? Well, the data can’t tell us this at the moment, but I’m leaning towards it being down to the fact that the grappling aspect of MMA has such a key influence on the movements and winning positions of a fight. This does not exist in purely striking sports, so what we use in those sports as a predictive factor just does not cross over. Of course, as with all scientific studies, another explanation could be that as each of these studies take a snapshot of different years, each result might be a complete anomaly, and other studies might get different results. For instance, a recent study found that the win:loss ratio of 1,284 MMA fighters could be predicted by their ape ratio. This result shows, however, that only 0.8% of the variance in the win:loss ratio can be explained by the ape index, which is exceptionally low, and could be casued by the large sample size used.
So , whilst technique use at heavyweight and featherweight may be affected by body size differences between opponents, there is no real evidence that this leads to more wins or losses, or a higher ranking over time. Indeed, other results from these studies show that age is actually a much better predictor of success, both in the short and long term. And, when it comes to anthropometry, how much weight a fighter can regain after their weight cut and weigh in seems to be far more important than height or limb length when it comes to winning or losing. Most damning for the height and reach hypothesis, however, is that there is arguably more evidence that being taller or longer is a negative factor than there is for it being a positive one.
In conclusion, whilst there’s no reason for promoters or TV/streaming companies to stop displaying height and reach information at the start of a bout, it seems most likely that these measurements have little to no influence on who wins or loses. Now if you’re interested in predicted who wins for betting purposes or you’re a coach/fighter looking to plan out your tactics for your next bout, this should be information you take into account, because if you’re basing your plans on height and reach, you may be disappointed more often than not!
Until next time, good luck, and have fun!
Coswig, V., Miarka, B., Pires, D., da Silva, L., Bartel, C., Del Vecchio F., (2018), Weight Regain, but not Weight Loss is Related to Competitive Success in Real-Life Mixed Martial Arts Competition, International Journal of Sport Nutrition and Exercise Metabolism
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James, L., Robertson, S., Haff, G., Beckman, E., Kelly, V., (2017), Identifying the Performance Characteristics of a Winning Outcome in Elite Mixed Martial Arts Competition, Journal of Science and Medicine in Sport 20:3
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Kirk, C., (2018), Does Anthropometry Influence Technical Factors in Competitive Mixed Martial Arts?, Human Movement 19:2
Kirk, C., (2018), The Relationship Between Age and Divisional Rank in Professional Mixed Martial Arts, Facta Universitatis Series: Physical Education and Sport 16:1
Monson, T., Brasil, M., Hlusko, L., (2018), Allometric Variation in Modern Humans and the Relationship Between Body Proportions and Elite Athletic Success, Journal of Anthropology of Sport and Physical Education 3