Taken from the inside howrse blog: First, they take the 10,000 most skilled horses for each player and multiply their total skill points by two : Next, they multiply this value by the sum of all these horses’ age (capped at 30 years old per horse) and apply a power to it : Then, they divide the result by the number of horses owned by the player and apply another power to it : Finally, they multiply the value by the number of passes bought as well as seniority: The formula as a whole looks like this: