Whether it turns out folly or genius, the hiring of Mike Macdonald as Seahawks head coach is John Schneider’s biggest gamble. High stakes, at that. The hiring, which replaces revered and beloved Pete Carroll, has been hailed as a victory by many NFL observers. Despite his youth (36) and scant resume, Macdonald is considered a prodigy among those whose job it is to devise ways to prevent 21st century offenses from scoring touchdowns.