I knew better.

Last week’s column finished by recommending that you avoid “hiring yourself” when filling management positions. It closed with a clincher: “After all, one of the most basic principles of information technology is to eliminate redundancy.” Jonathon Kass responded perceptively:

“This struck me as an odd statement — probably just because I’ve been focused for the last few months on our own department’s business continuity planning, availability stats, and general architecture needs. Of course, in that domain, redundancy is some of the core of what IT must provide – redundancy of a form that ensures the ongoing availability of critical services – redundant hardware, network connectivity, power, air conditioning, etc.”

Mr. Kass didn’t argue with the column’s general principle, but did suggest that the continuity thought process is relevant for staffing, and in particular for cross-training and succession planning. To which I say … after all, one of the basic principles of information technology is to plan redundancy. It’s as valid when choosing managers as it is with information engineering.

The main point is that the person in charge has a huge impact on performance. Twice. A week ago it was all about you. If you’ve been in charge for any length of time, and nothing is changing or the situation is deteriorating further, go back and read it.

Here’s the other half: Leaders at all levels can cause or encourage poor performance, which cascades in a sort of chain reaction through the chain of command. This makes it … what? A chain of command reaction? A bad leader recruits bad leaders or prevents good leaders from leading well. Those bad or prevented leaders do the same in turn. And so on, and so on, and so on.

In trying to sort out which of your managers can’t be rehabilitated, an excellent source of information is the collection of performance reviews they’ve filed. When you review them, you’ll almost certainly find some managers who have nothing but problem employees reporting to them. Put these managers at the top of the list of managers who need to find other opportunities — with your competitors if at all possible.

But keep the people who reported to them. I’ve lost track of how often bad managers hide and suppress the abilities of the good people they supervise.

Very recently I heard yet another example — the manager of a small workgroup that consistently hired outside consultants whenever difficult work was assigned, because her direct reports just didn’t have the skills. The recently hired CIO terminated her, asking her workgroup to take on a couple of challenging projects. You know what’s coming: They stepped up to the plate and hit, if not home runs, at least solid singles and doubles — good employees made bad by their manager.

You’ll also find managers who have only stars and superstars on their teams. Some really might be excellent leaders who recognize and insist on talent and drive among those they hire. You can recognize them through the performance reviews they authored. You’ll read nuanced (there’s that word again) accounts of each individual’s strengths and how they contribute to the overall health of the organization. And even the strongest individuals will have received suggestions for areas that would benefit from additional focus and attention.

But most managers with only stars and superstars will have written, over and over again, “Doing fine — keep up the good work.” They might have low standards. They might simply be afraid to lead, erroneously using the approval of those who report to them as a gauge of their abilities. Or, they might have misplaced their loyalty, figuring they’re competing with their peers for the raise pool, and are responsible for obtaining as much of it as possible for their team. (In some circumstances, this loyalty isn’t misplaced, either — it’s required to avoid having their peers raid the raise pool, leaving their employees high and dry. If that’s been the case, don’t blame the managers. Fix the circumstances.)

Keep every strong leader you possibly can. You’ll need them all. Can you turn the others around? They’ll take a lot of your time and attention; many will fail anyway.

Give them the attention. But not a lot of time.

Those who have the potential will demonstrate it quickly given an environment that encourages it. The rest? Give them time and they’ll figure they have all the time in the world.

Which is, of course, just another symptom of the problem.