My admittedly intuitive take on this is a little different than yours Chris. Back when it was not unusual for a horse to run upwards of 20 times, horses would establish a level of ability, say for purposes of example a TG 8. Let's say the horse in question runs a 4 or 5. Despite the out-of-the-ordinary effort, the horse would nonetheless run its "regular turn"(ie short rest) and flop, or as it was came to be called "bounce." In contrast, horses today, while they may run faster, do not run nearly as often & many trainers both consult sheets and sheets players and/or know and understand the bounce concept. As a result, horses do not bounce as often as they used to, which is what the research seems to indicate. Despite this, sheets sellers and sheets users seem IMHO to be operating on the assumption that there has been no change in the last 30 yrs, not to mention the related question of whether a significant no. of so-called bounces today have anything to do with the original concept.

PS to PP: I'll give your latest post some thought & get back to you, but I have to admit that I'll also be thinking about how & why you're storing info back to around the time I was born.