Boston Celtics coach Doc Rivers is picking his team to repeat as NBA champions and hoist their 18th championship banner, according to the Boston Herald.Doc Rivers says the Celtics will have to be better than they were last year to repeat as NBA champions.In a survey of the NBA's general managers conducted by NBA.com, 46 percent of those responding picked the Los Angeles Lakers to win the championship this season. Just 19 percent picked the Celtics to repeat. Source: ESPN.com