One of my favourite management books is Good to Great. Jim Collins studies companies over several decades and tried to understand why some succeeded more than the others. He defines Level 5 leadership as the highest form of leadership which helped the really great companies surpass other by a good distance. Think Amex vs. Others, for example. The deep analysis returned a very simple answer. Discipline. He divided it further – Disciplined People, Disciplined Thought and Disciplined Action.
I say mindset since most managers whine about resources a lot. Either they have too many to manage, or too few, or too unskilled, or ambitious… In a perfect managerial world, they have the perfect set of resources for the jobs at hand and then they can guarantee success! Isn't this though the crux of managerial capability to use available resources to deliver best possible results? Isn't that how you would determine the best managers? The best managers constantly re-assemble, re-assign, train, develop, remove, create, push and shove till they get the best combination to deliver on their most important goals. Hence, its a mindset issue. Managers get into mindset that they forget that this is the most important part of their job, They worry about delegating (and still controlling quality), about individual egos, the pain of letting go people from their teams and so on and so forth. They do not take the tough decisions. Or a lot of times, any decision at all.
The reality is that managers work at a fraction of their potential. The answer to infinite bandwidth lies within and is completely within their own control. I would love to hear what managers think.