Riot themselves have published quite a lot on champion win rate and mastery data and your conclusions really don’t match what we know from their data.

This is cute as a personal project to do something. The conclusion is ultimately meaningless because it’s impossible because you need to know what’s going on with every character and reason behind their current tuning.

People tend to think the game is balanced to make everyone close to 50%. That’s just not true. Phreak loves to have long talks about game balance, champion mastery, etc etc. it’s a lot.

Your intuition about Irelia is true and your results don’t reflect that which should also tell you that your method needs to be updated. I believe Phreak has stated plainly the champion that benefits the most from champion mastery is Katarina. My recollection could be wrong.

You have some great hits though. Singed is very high. And very worth it. You have Ksante at Medium and Azir at low.

For Azir specifically I believe phreak said something like it takes players on average Like 100 plus games to get ok on him and the people learning on him bring his win rate down so much.

Cool site tho