The Golden State Warriors went into halftime of Game 1 of the 2016 NBA Finals with a nine-point lead over the visiting Cleveland Cavaliers, but a poor defensive start to the third quarter and some strong shotmaking by the Cavs cut that lead down in a heartbeat, leading Warriors coach Steve Kerr to call a timeout to talk it over ... and, evidently, work out some frustration on his whiteboard in the process: [ Follow Dunks Don't Lie on Tumblr: The best slams from all of basketball] Steve Kerr is not happy breaks clipboard. pic.twitter.com/QdQgINvos5 — ⓂarcusD (@_MarcusD_) June 3, 2016 Sure, Kerr might throw out the laid-back West Coast vibe, but don't let the smooth taste fool you; he's as competitive as they come, and apparently, he's got hands of stone. This isn't the first time this season Kerr's been caught assaulting his whiteboard during a nationally televised game: ... nor is it the first time he's broken one, according to Brian Mahoney of the Associated Press : The shooting and passing weren't good, though apparently coach Steve Kerr's clipboard toss was impressive. ''He broke the clipboard, then threw it,'' Draymond Green corrected. [...] ''Coach Kerr got on us...