User blog comment:BIA-Kaboose/The Problem Behind Balance/@comment-24242333-20131211145617/@comment-8267817-20131211162629

Allow me to restate what I said. Riot notices us sure, but a lot of the balancing is based on pro players, not average players. Which is frustrating because it means that a lot of champions are almost never seen in normal games because they are percieved as bad by normal, average players.

This creates a problem because if only a few pro players play a champion like Shaco, then Riot can't effectively balance them because they can't feasibly collect enough data on them to see how good they are in comparison to other champions, because the data is so sparse.

The problem is that some champions that should be good simply aren't.