Seeing some people sell their backup foals/pups as newborns got me wondering: what got the backup thing started?

I thought I knew, but maybe I'm remembering wrong, lol. The way I understood it was that foals had a very, very small chance of not surviving, so people would do a backup breeding to make sure they still had a foal from that breeding pair. Was that ever actually a thing on HP? If it was, is it still a possibility? Or is the whole backup thing a habit that got carried over from Horseland?

On HL it was a legit backup because there was that small chance that offspring would not be viable. On HP it's more of a safety net if you forget to breed and don't want to have to do a retirement breeding. 

Ooooh okay, that makes sense. Thanks! =)