LAS VEGAS — Ninety minutes before tip-off Saturday night, in the visiting locker room at T-Mobile Arena, Steve Kerr tried to do a favor for one of his best friends. The Warriors' head coach told Lakers head coach Luke Walton the first play he planned to run. Walton became one of coaching's hottest commodities after posting a 39-4 record, including a record 24-0 start, as the Warriors' interim head coach last season while Kerr recovered from complications from back surgery. Los Angeles lost Kobe Bryant from a team that finished last season with the league's second-worst record at 17-65. In his first campaign as a full-time head coach, Walton is building around a young core of D'Angelo Russell, Julius Randle, Jordan Clarkson and Brandon Ingram. With less than two weeks until his team's regular-season opener, he is still teaching players his offensive and defensive systems. Before games during his two seasons with Golden State, Walton often waited to shower and change into a suit until the rest of the team was already dressed. In his first preseason with the Lakers, Walton is making a concerted effort to join his players for "The Star-Spangled Banner." Being the head coach of...