As a Master Tier player on both EUW and EUNE servers that cares deeply about the state of League of Legends, I had enough of the lack of high quality educational material about the game.
By the way - an improved, enriched and even more detailed version for Season 7 is out an.
So about a year ago, I used my experience as a real life teacher and high elo player and wrote what turned out to be the best selling ebook about improving at League of Legends on Amazon for Season 6 - 30 Days to Diamond.
As a Master Tier player on both EUW and EUNE servers that cares deeply about the state of League of Legends, I had enough of the lack of high quality educational material about the game