I have been researching used dressage saddles for some time now. I'm seeing a large number of 18", 19" and even 20" seats available. Not having gone to a tack shop and sat in saddles in a long while, has seat sizing changed? Those seem like very large seat sizes to me. Have dressage saddle makers changed how they fit the human ass to account for such sizing? I can't imagine it's only "larger boned" people selling their saddles to account for it. As I said, merely a curiosity.