Official Konami COSSY

The Yu-Gi-Oh! COSSY is for ranking players skills in the Yu-Gi-Oh! Trading Card Game. It is short for Card Game Official Tournament Support System.

It ranks players all around the world according to the Elo rating system and tells them where they stand in comparison to other players, in both global and national rankings in official tournaments. As of March 23rd 2017, the COSSY system has been discontinued and replaced with the Konami Card Game Network system. ^[1]