LONDON: Arsenal begin the defense of their Premier League title as one of the few clubs untouched by a close season of managerial upheaval that has transformed the landscape of English football. While Mikel Arteta’s methods are tested and trusted at Arsenal after nearly seven years at the helm, it is all change elsewhere with chief rivals Manchester City, Liverpool and Chelsea all entering new eras with a new man in charge. In total, a record nine Premier League clubs will begin the season with a new permanent manager. Whether the managerial merry-go-round eases the way for Arsenal to win back-to-back titles or sparks one of the most unpredictable seasons in years may prove the defining question.