Is it accurate to have boys and girls in the Qing palace? The uterine evacuation algorithm, also known as the ovulation period algorithm, is an ancient method for predicting the gender of the fetus. The basic idea is to calculate the time of conception and the gender of the fetus based on the woman\’s menstrual cycle and age. Although widely circulated among the people, the scientific nature of the Qing Palace algorithm has been questioned. The following will be discussed from multiple aspects to reveal the accuracy of the Qing Palace algorithm. moon