SAN FRANCISCO – The list of prohibitive sports underdogs that “shocked the world” with their championship feats is expansive and deep, but the 1975 Warriors surely rank among those at the top.According to Rick Barry, their highly opinionated floor leader, it stands above all others.“Biggest Finals upset in the history of major sports in the United States,” Barry said Friday at Chase Center as that team celebrated its 50th anniversary. “I defy anybody to point something else out that was as dramatic as what we did.”Barry was referring Golden State’s astonishing victory over the Washington Bullets, whose 60-22 record – 30-13 once the calendar flipped to 1975 – made them heavy favorites. The Warriors not only won but did so in a sweep – the only sweep in the ’75 postseason.It was an epic achievement, considering Washington’s roster included four All-Stars, two of whom reached the Hall of Fame. The Warriors’ lone All-Star, Barry, also is in the Hall.Yet national reaction was relatively muted.Charles Dudley, a backup guard, hopes to change that. He has wrapped production on a documentary, “The...