Of course, if we were able to watch a great athlete training, or a great writer writing, or a great coder coding, we would see that honing a strength is hard work—it is by no means easy to find that incremental margin of performance when you are already operating at a high level—and that a strength is not where we are most “finished” but in fact where we are most productively challenged. Yet we are told to resist the temptation to “just” play to our strengths, and instead to work constantly on our weaknesses. In common parlance, we are told to avoid “running around our backhand.” This betrays, perhaps, a misunderstanding of what a strength actually is. It is not, for each of us, where performance is easiest—it is where performance is most impactful and increasing.

To achieve the highest level of talent density you have to be prepared to make tough calls. If you’re serious about talent density, you have to get in the habit of doing something a lot harder: firing a good employee when you think you can get a great one.

One of the reasons this is so difficult in many companies is because business leaders are continually telling their employees, “We are a family.” But a high-talent-density work environment is not a family.

We encourage our managers to apply the Keeper Test regularly. But we are very careful to not have any firing quotas or ranking system. Rank-and-yank or “you must let go of X percent of your people” is just the type of rule-based process that we try to avoid. More important, these methods get managers to let go of mediocre employees, but they kill teamwork at the same time. I want our high-performing employees to compete against Netflix’s competitors, not one another. With rank-and-yank what you gain in talent density you lose in reduced collaboration.

Fortunately, there is no reason to choose between high talent density and strong collaboration. With the Keeper Test we can achieve both. That’s because there is one critical way we are not like a professional sports team. On the Netflix team there is no fixed number of slots. Our sport isn’t being played to a rule book and we don’t have limits on how many people we play with. One employee doesn’t have to lose for the other to win. On the contrary, the more excellence we have on the team, the more we accomplish. The more we accomplish, the more we grow. The more we grow, the more positions we add to our roster. The more positions we add, the more space there is for high-performing talent.

In many large organizations, the challenge is often diagnosed as internal. That is, the organization’s competitive problems may be much lighter than the obstacles imposed by its own outdated routines, bureaucracy, pools of entrenched interests, lack of cooperation across units, and plain-old bad management. Thus, the guiding policy lies in the realm of reorganization and renewal. And the set of coherent actions are changes in people, power, and procedures. In other cases the challenge may be building or deepening competitive advantage by pushing the frontiers of organizational capability.

Whenever a company succeeds greatly there is a complementary story of impeded competitive response. Sometimes the impediment is the innovator’s patent or similar protection, but more often it is an unwillingness or inability to replicate the innovator’s policies.