Rotationally efficient swings generate about half of their speed in the first half of the swing, where speed is primarily generated by the hips and shoulders versus the arms and wrists. The target zone is about 45% to 55% of your speed in the first half. Anything lower than this will result in an Energy Transfer score less than 100. This usually indicates an over-reliance on the arms (for example, casting the arms away from the body). Any speed in or above the target zone will receive an Energy Transfer score of 100. Even though we don’t penalize you for exceeding the target zone, it might be difficult to control the bat and adapt to pitches in a real game scenario. You’re probably swinging out of your shoes!