If Singed winrate skyrockets, it's because of retired mains.

A lot of Singed mains have retired because of the state of their champ. He simply wasn't the fun AP Bruiser he used to be. Now that he is starting to be again, they are back and winning a lot. Because lets face it, they have been playing for years on a crippled champion. Now that Singed is back to a playable state, they are going to win and gain rank until they are at an actually fitting elo to their skill.

I do hope Riot keeps that in minds before they nerf him.