When a company needs a supervisor for a team, senior leaders often anoint the team’s most productive performer. Some of these stars succeed in their new role as manager; many others do not. And when they fail, they tend to leave the organization, costing the company double: Not only has the team lost its new manager, but it’s also lost the best individual contributor. And the failure can be personally costly for the new manager, causing them to doubt their skills, smarts, and future career path. Everyone loses.