Years ago, we had Ranking and Rating. As a manager no matter what rating you gave your employee (meets, exceeds, does not meets, etc). you went into a conference room with your peer managers and compared ratings. It was a check and balance system. Some managers over-rated their buddies but the other managers ensured that equal performance got equal ratings. I've even seen employees rating get improved by other managers. Remember, this was all in the past.
Fast forward to today. Nowadays, a manager is given a bucket of stock that he can assign to each of his employees. It is solely that person who decides what stock level to give that employee. It is rarely reviewed (as long as he meets his budget) and the poor employee who received SL4 or SL5 is pretty much on his own.
Unfortunately this is the system. I and only I chose to work here.