A recent trend in DA stables (whether they are registered with the #HorseArt-RPG (https://www.deviantart.com/horseart-rpg) or other horse art clubs) has been to use randomized stats and events for your horses. Some only use it for breeding and foaling, others use it only for competitions, and some just use it for the horse's general life time. Or all three and many other uses.
These random outcomes are used to do things like determine if a breeding was successful or not or how healthy a foal is when it was born. For competitions its used to find out if your horse won, placed, or just lost at a usually made up list of events, usually these don't include club-hosted competitions