@meaStyy-1739 Calm down. Go outside. Take a walk.
@Tactician-11177 The actual comparison is not the rules of the match, such as how a bishop moves (which for Overwatch are either published or relatively easy to test), but the rating system. In a chess association or tournament you know the exact rules of how your rating will change with each game. Given the rating of the two players, you can calculate how your rating changes with a calculator and then verify that the official number matches. See http://www.glicko.net/ratings/rating.system.pdf for an example (US Chess Federation rules).
This is not the case for overwatch, in which in my summary, How Competitive Skill Rating Works (Season 11), is vague by necessity, in many places. Overwatch could stand a lot more tranparency in its rating system.