OverPicker is mostly based in the Hero Picker created by jazzmasta25
Hero Picker was the first source for this picker before, but right now the page has my own data and ideas about interactions in the game.
I create a tier list based in the Overbuff stats, this tiers are adjusted taking into consideration the win rate and the pick rate.
I'm trying to have a general tier list make out of my sources, right now I'm using Metabomb
1 Tip for Every Hero Series made for KarQ, is a great inspiration to know counters for every hero in the game.
Thought Process Series made for SVB have great ideas about what heroes are good with others and also help me knowing other counters.
A List on All Existing Compositions in Overwatch made for Shielder_OW, is a good summary of many of the game's most important compositions in the game.
KarQ Tier Lists, KarQ made a lot of informal Tierlist about sinergies and counters that I take in consideration