Key Players: The key players in this scenario are the players who are involved in the knockout stages, which is where they perform their best work and put on the most pressure.

Rotating: The rotating system in question involves the players rotating between positions throughout the game, allowing them to switch roles and adapt to different situations or tasks. This allows each player to focus more fully on their role during a particular stage of the game, reducing fatigue and increasing performance.

Save energy: In the knockouts, there is often a high demand for energy from the players, as they need to maintain their performance levels and make crucial decisions. By rotating the players, it reduces the amount of energy that needs to be expended by each player, which can lead to increased performance and reduced fatigue.

Overall, the rotating system in the knockouts helps to ensure that the players are well-rested and focused, while also providing them with the opportunity to make the most out of their time on the field. It's a simple yet effective way to save energy and improve overall performance.