Houston Rockets center Yao Ming (11) of China defends against players of Dallas Mavericks as they try to get a shot in the NBA exhibition basketball game in Huston on Thursday, Oct. 18, 2007.

Houston Rockets center Yao Ming (11) of China tries to slow down Dallas Mavericks' player as he drives the ball forward in the NBA exhibition basketball game in Huston on Thursday, Oct. 18, 2007. Oct. 20 - China's star center Yao Ming impressed his adversaries in the game against Dallas Mavericks Thursday, the Houston Chronicle reported.Since most of Mavericks' starters didn't play, with nearly a full foot of height advantage against the mini-Mavs, in 20 minutes, Yao had 19 points on 8-of-11 shooting in the 104-90 victory."What impresses me most is that he is not passive anymore," said the Mavericks' center Darvin Ham, who missed last two seasons."He takes it right at you and punishes you. He is bringing the fight to the post. If Houston continues to play through him, they will be a very tough team to beat."I was thoroughly impressed by how much he has improved," he added.Yao feels comfortable in coach Rick Adelman's system and should deliver first-round value if he stays healthy.