The sport was improved during the Tang Dynasty (618–907). First of all, the feather-stuffed ball was replaced by an air-filled ball with a two-layered hull. Also, two different types of goal posts emerged: One was made by setting up posts with a net between them and the other consisted of just one goal post in the middle of the field. The Tang Dynasty capital of Chang'an was filled with "cuju" fields, in the backyards of large mansions, and some were even established in the grounds of the palaces. Soldiers who belonged to the imperial army and Gold Bird Guard often formed "cuju" teams for the delight of the emperor and his court. The level of female "cuju" teams also improved. Records indicate that once a 17-year-old girl beat a team of army soldiers. "Cuju" even became popular amongst the scholars and intellectuals, and if a courtier lacked skill in the game, he could pardon himself by acting as a scorekeeper.