2) Getting the tactics wrong
To be honest, no club deserves to win the Premier League if they get thumped by their title contenders on more than one occasion. Losing 6-3, 5-1 and 6-0 all in one season to Manchester City, Liverpool and Chelsea respectively only meant that Wenger left his tactical mind at home during big games.
Playing Santi Cazorla and Tomas Rosicky on the flanks, substituting Giroud with an inexperienced youngster Yaya Sanogo during the crucial stages of the game with Manchester City and resting Mathieu Flamini (Arsenal’s best CDM by a country mile) in the games against Chelsea and Liverpool are an evidence for Arsenal’s tactical failure this season.
But by far the most bizarre decision taken by Wenger was to play Alex Oxlade Chamberlein, an attacking winger by trade, in a Central Midfield role against Chelsea. What was he thinking? Wenger should realize that if he is serious about winning the title with Arsenal then he needs to get his tactics right in games that actually mattered.