The swing frequency is moderated from left to right.
1. Top rotation - the modulation is over 2, and the downward spin is 1. The ball sent by HUI PANG will rotate upward.
2. Downward spiral --- modulation is 1, lower rotation is more than 2. The ball sent by HUI PANG will be sent downward.
3. No rotation - the same number will be rotated in the modulation, and the ball sent out by HUI PANG will not rotate.