If there's one absolute, it's that young managers of people would like all performance-related items to be black and white.
When's the last time managing people didn't include shades of gray?
One of the most powerful things we can do as HR pros is make our managers comfortable with shades of gray, knowing that they can be the judge and jury when it comes to the statements they make related to someone's performance.
Coaches should coach. That means your managers of people have to be the experts of good vs. great related to the people/job combinations they manage.
You're doing good, not great. Good is good. Here's why you fit that definition. If you want to get the next level and be great in this area, I've got see more of <insert gold>.
Help your managers do that, and you'll be in the 95th percentile. The good great end.