“If they get into the postseason — and I think they will now — they’ll win the World Series,” said the scout, who spoke on the condition of anonymity because he’s employed by a rival club. A bold prediction considering the downward arc the A’s traced over the past month, going from four games up in the AL West and the best record in baseball to, at one point, 11 games behind the Angels and a slim edge for a wild-card spot. Fans and national media have started talking about “biggest collapses of all time,” linking the A’s with teams like the 1964 Phillies, the 1993 Giants, the 2007 Mets, the 2011 Red Sox and Braves. Most big-league scouts and executives, though, applaud the moves that general manager Billy Beane made before the trade deadline and believe Oakland has what it takes to contend.