These are the top 10 most practiced martial arts in the world. These are numbers just estimations based on Google searches, and probably mostly industry hype. My best guess is the numbers are probably all equally inflated so that the proportions of the true numbers would be about the same...
The hardest and least accurate number for all of these is for Wrestling. My estimation was somewhere between 16,000,000 and 280,000,000 depending on what you call wrestling. One of the things I had to take into consideration is that most wrestlers only wrestle for a few years as a youth. If you have better numbers for the total numbers of people wrestling globally, please post those numbers and links to your sources in Self Defense Evolution.
The finding is bizarre: not only is Tai Chi the most commonly practiced martial art in the world, but it is practiced more than all other martial arts combined. On one hand this is bad news for humanity because of quality control problems in Tai Chi, but on the other hand there is opportunity here because Tai Chi is rife with potential martial arts application for those who do free sparring. For example, in the following MMA Shredded video, more of the techniques than not are expressed in Yang style forms, especially #2:
