How many horses can you fit into a 20X60 meter pen?

…it depends how high you stack them.
Though I recognize that the warm-up ring is a necessary evil at horse shows, I still don’t understand why so many people riding in it are either feckless or believe they OWN the ring. I mean seriously, I don’t care how $$$$$$ your horse is or that you’re riding a higher level than I am, it doesn’t give you the right to throw common courtesy out the window and try to run me over. Also, I get that there are green horses (I have one!), but let’s all just agree not to take the screaming harpy on a string into the warm-up ring with 47 other horses when you have other options (when you don’t have other options, I get it. Also I feel your pain. :().