The top picks globally to counter 제드 include 칼리스타, 징크스, and 케이틀린. These are all good at countering 제드 with high win rates over 55%. Even if these 제드 counter picks are not picked in the same position as you, it's not smart to take him into any of these matchups. They will likely win against 제드.
Conversely, if the opposite team brings either 스카너 or 갈리오, you should strongly think about choosing him, as he easily destroys these selections with win rates over 52% against each ofthem.