Being in control. Movement cannot exist if you do not have stable joints for muscles to act upon. Focusing on true core strength and joint control is vital to your athletic foundation.
Full range of motion. If you cannot move freely you are limited. Focusing on optimizing your mobility decreases injury risk and improves strength, speed, and power.
No wasted motion. If you cannot transfer energy properly you are not being the best athlete you can be. Perfecting technique and consistency with change of direction, acceleration, and decceleration produces an elite athlete.