SAN FRANCISCO – While the Warriors were careening about the corridors of mediocrity last season, coach Steve Kerr saw disappointment beneath the mounting injuries, the torrent of turnovers and mindless deviations from the game plan, all of which torched hope.Nothing bruised Kerr’s psyche more than what he saw in the mirror. Himself. A veteran coach, lavishly decorated, operating below his standard.Scouts around the league noticed it, and so did several internal observers. So, too, did Kerr.“I didn’t have a great year,” he conceded to NBC Sports Bay Area the other day on a “Dubs Talk” podcast interview. “I think coaches are similar to players. You have years that are better than others, you have years that are worse than others.”Call it a slump that also had breakthrough moments, one of which came in November after Kerr shouldered much of the blame after a home loss to Houston. Jimmy Butler III later stood in the locker room, pointed toward the white board – it was obscured by a cloth – and said the game plan had everything needed to win games was posted.“Don’t listen to Steve,” Butler said....