[wisty]

OK, but how do they know what needs to be done?

A baseball coach knows if the pitcher isn't doing so well, because he's watched the games. How does a manager know if the new API is unwieldy, or if errors in one component are causing serious grief?

I mean, you can ask employees to blame their peers, but some won't want to, and some will be a little too eager.

[peterwwillis]

There is more going on in baseball than that. Similarly, there is more going on in software dev team management than that.

https://en.wikipedia.org/wiki/Coach_%28baseball%29