I don't know how anybody can say with any confidence that AVB is a good manager. People say he is tactically astute. He is actually pretty awful tactically from what I've seen. He plays the same tactics every game, plays a high line with players unsuitable as with Chelsea and plays a high line against really fast attackers. If he was great tactically he could develop a tactic which would suit his players but he instead plays a style totally unsuited to his players. Bale single handedly won them loads of games last season to disguise his system's flaws