We learned that a company with really dense talent is a company everyone wants to work for. High performers especially thrive in environments where the overall talent density is high.

Our employees were learning more from one another and teams were accomplishing more—faster. This was increasing individual motivation and satisfaction and leading the entire company to get more done. We found that being surrounded by the best catapulted already good work to a whole new level.

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.

Culture isn’t something you can build up and then ignore. At Netflix, we are constantly debating our culture and expecting it will continually evolve. To build a team that is innovative, fast, and flexible, keep things a little bit loose. Welcome constant change. Operate a little closer toward the edge of chaos. Don’t provide a musical score and build a symphonic orchestra. Work on creating those jazz conditions and hire the type of employees who long to be part of an improvisational band. When it all comes together, the music is beautiful.

At the end of the day, the best way to respect and reward the A players on your team is to surround them with other A players. This is how you attract more A players. And it means you must invest as much energy into hiring as you expect the team to invest in their jobs. You cannot expect someone to keep giving all of themselves if you put someone alongside them who isn’t willing to do the same. You need to be as unreasonable in how you build your team as you are in how you build your product or experience.