Crowd density is certainly the key here. Over a certain density crowds move like a liquid. Under a certain density crowds get much more difficult to model. Thi

Crowd density is certainly the key here. Over a certain density crowds move like a liquid. Under a certain density crowds get much more difficult to model. This is not new in any way, btw. This paper seems to specifically address the running of the bulls. https://www.science.org/doi/10.1126/science.aat9891 https://www.science.org/doi/10.1126/science.aat9891