Question: The 1998–99 NBA season was the Mavericks' 19th season in the NBA, in the offseason, the Mavericks traded their top draft pick Robert Traylor to the Milwaukee Bucks for which rookie, a German professional basketball player for the Dallas Mavericks of the National Basketball Association (NBA), and considered to be one of the greatest power forwards of all time?
{'answer': 'Dirk Werner Nowitzki', 'supporting_facts': [['1998–99 Dallas Mavericks season', 1], ['Dirk Nowitzki', 0]]}