 NBA and free agent guard Klay Thompson signs a three-year deal with the Dallas Mavericks after 13 seasons and four championships with Golden State. It required a sign-and-trade that involved the Hornets who received forward Josh Green from Dallas while sending two second-round picks to the Warriors. Green averaged eight points per game last season for the Mavericks. Boston Celtics signed star Jason Tatum to a five-year contract extension worth $314 million.