Self help book on elo rating for gamers

I will require a self help book for gamers without the mathematics and understandable by the average joe.
It will be a non-technical ebook on a rather technical topic of the "elo rating system"
https://en.wikipedia.org/wiki/Elo_rating_system

Have you read A Brief History of Time??
I would like it to be similar to that, explaining complex topics without the formulas. It should be interesting with practical explanations and fully understandable for any person who does not know elo rating system at all!

If you have understood the above criteria and have knowledge over Chess and elo rating system, you can bid in my project.

There is no boundary on length of this topic as there will be a lot more topics to create a self help book for Gamers.

I will need you to start immediately with first draft latest by tomorrow.

Thank you