to know it is the kind of content for hotlines

Watching this hbo show, just as Golden Tempo wins the Belmont

Very good acting 
Starring Dustin Hoffman

https://www.imdb.com/title/tt1844125/fullcredits/

In this episode nick nolte tells the ambitious jockey to just let the young
inexperienced horse to do the work, it will  win on its own 

But when she is riding, even as she is way ahead, she used the crop

He gets very mad even tho the horse won and he throws her crop in the trash
She said she felt the horse was going too steady

He says the horse has to learn on its own

No really good explanation either way why she needed the crop or why threw
it away

I was hoping for an explanation but the writing on this piece was obtuse 

In fact, he seemed unfazed by other jockeys using crops in later episodes