Fair games have legible rules and The more legible the rules of the game, the more straightforward it is to optimize for the game. Which means that the more fair you make a game, the more straightforward it is to optimize for that game.
If a game is straightforward to optimize for there’s a more direct relationship between time and resources you put in and your output. This direct input-output relationship means that people who have the time and resources to put into optimizing for the game will have an advantage at the game. The classic example is college admissions. First, they used grades and standardized test scores that can be optimized by hiring tutors and spending time studying, which led to wealthy kids who could afford to hire a tutor and spend time studying doing better. So the colleges added extracurriculars and ‘experience’ as admissions criteria to make admissions more fair. But it turns out extracurriculars can also be optimized with time and money.
I would argue that the only way that colleges would be able to achieve a goal of admitting poor and underrepresented students is through discretion - ie. Making the game unfair.
If there is a specific way to optimize a game, the variance of the people playing that game will go down. Making a game more fair reduces its variance
This note might want to be combined with The more legible the rules of the game, the more straightforward it is to optimize for the game