One of the most common questions I receive from Zed Run stables is, “what is the best breeding strategy?”. This is a complicated question, but with the return of breeding it seems time to make a basic plan available. This article will take a quick dive into a strategy using only four genesis horses.
Inbreeding is crucially important to IRL horse racing. They are called thoroughbreds because they are thoroughly inbred. My previous article covering Medina Spirit (link) shows the Derby winner’s lineage, and a genetic study from 2005 found that 95% of 500,000 horses are bred from 28 foundational horses and one super stud (link). Zed Run’s breeding strategy will follow this same plan.
Zed Run tells us that “you cannot breed with your brother, sister, parents, or grandparents.” However, how do we define a sibling? IRL horse racing traces family lineage through the mare’s line and so does Zed Run. You can breed a sire with two different mares and subsequently breed those offspring.
The 4 Horse Plan
To use this basic breeding plan, you will need to find the genetics of 4 genesis horses. If stables do not own a genesis horse, they can still leverage the community to find the necessary pieces. Stables can use Twitter and Discord to find the other stable to request breeding and foal trading options. The plan below shows how 2 gen mares breeding with 2 gen stallions create horses that are technically not siblings. They are then bred with the opposite tree’s stallion, and bred together.
In conclusion, this is not a deep dive into a breeding strategy. It is a basic inbreeding playbook with the fewest genesis horses used. The Zed Run genetic algorithm is complex and will take a multitude of generations to grasp after trial and error.