It’s not always easy to pin down what managers do, but one thing is for sure: bad managers hurt teams. It’s an accepted truth.

I’ve spent a good amount of time thinking about why bad managers hurt productivity and why good managers help it. There’s a metaphor I like that explains the difference between good managers and bad managers.

A manager is a multiplier.

In software, we have the concept of the 10x developer–the person who can do the work of ten regular developers. While I’m certain that a manager can’t take a functioning team and make it ten times better, they can make things two times better. A 2x manager.

A 2x manager would be rare, but a good managers should make teams slightly better. Making a team 25% better should be considered an accomplishment.

Bad managers have a multiplier of less than one. A 0.5x manager makes a team half as effective as they should be. They hurt teams by creating choke-points, obstacles and distractions.

Bad managers also hurt teams by causing people to quit. Factoring in the impact of employee leaving, it’s conceivable for a bad manager to have multiplier approaching zero.

In extreme situations, a bad manager might even have a multiplier below zero. A manager that destroys the value other teams create while also running a team that doesn’t create any value would be an (unlikely) example.

Unfortunately, the average manager is not a 1x manager. We acknowledge this when we talk about management being a tax on an organization.

Replacing a manager can lead to large shifts of productivity. Going from a bad manager to a good one can feel like a 10x improvement. Conversely, replacing a good manager with a bad one can turn a great team into a poor one.

If you are managing others, you should do anything you can to increase your multiplier.