Individual errors and a lack of focus defensively were big contributing reasons behind the downfall and eventual departure of Arsene Wenger.
For all the attacking verve and incisive passing football he championed, the Frenchman struggled in his last five seasons or so to balance that with the need to master the more practical, defensive side of the game.
There were flirtations with different systems, the odd attempt at a team press, but, for the most part, it was all about winning the game in possession and to hell with what happened out of it.
Thus, his teams were plagued in the latter years of his tenure with the tendency to make glaring errors, forced and unforced, which became a regular source of goals and points for opposing sides.
A lack of direction on the pitch tended to compound that problem and, unsure of what to do next, Arsene’s sides simply carried on attacking.
The spectre of that attitude and lack of direction on the pitch still loom large and, with them, the reoccurring individual mistakes and lapses in concentration.
I admit, I had hoped in his work with the team over the summer, Unai Emery might have entirely eradicated that weak mentality and ill-discipline but, it has become abundantly clear, that was foolish of me.
Coaching this team into a better shape and a better mindset is going to take weeks and months on the training pitch. It is not just a formation change the manager has to introduce, it is a shift of epoch.
From one half of football to the next, this Arsenal side is a different beast. Here they are swashbuckling and wide open, and there they are rigid and overly focused on shape. The Chelsea match was no different in that regard.
Trying to get a consistent, 90-minute performance has so far eluded Emery but, as has become clear, that is not an easy feat to achieve.
There were flashes of his thinking and philosophy on show against Chelsea. They fashioned a stack of gilt-edge chances and did so in an unfussy, decisive sort of way. They were quicker to release the ball and the tempo in and out of possession was higher.
Defensively, in terms of what’s changed, you can see Emery favours a higher line in games where the striker is not particularly quick and you could see a better work rate from the midfield in terms of pressuring the opponent and winning the ball back proactively. Guendouzi, in particular, was excellent in this respect and led the team with tackles and interceptions.
That said, however, there remains a streak of errors and mental fragility in this team that, once again, cost us goals. Henrikh Mhikitaryan allowed Marcus Alonso to sprint into the space that he should have been covering for the first goal, realising his error much too late, while Shkodran Mustafi was caught the wrong side of Alvaro Morata when danger should have been apparent to him for the host’s second.
The third goal was the result of rank carelessness in possession from Alexandre Lacazette, made worse by his token and wholly inadequate efforts to win the ball back afterwards.
I understand that in most conceded goals, there is an element of blame to be apportioned to someone, and players not seeing things we believe they should is always apparent, but this happens to Arsenal far too often to be bad luck.
It is the result of years of self-rule on the pitch and attempting to instil a sense of responsibility for positioning and other facets of the defensive game is being subconsciously resisted by some.
Clearly, that has to change.
The players must think of the whole now, rather than the parts. Cutting out the mistakes and staying focussed for the entire match is going to be a team effort but each player must take greater responsibility.
Conceding five goals in the first two matches is not good enough by any stretch of the imagination, whoever the opposition happens to be.
Now we have dispensed with our opening two fixtures, nightmarish as they were for a new manager, it is time to start putting together a much more coherent performance. We need to see this team adopting and adapting to the demands of the manager and the vestiges of a now bygone era must start to be left behind.
In short, the mistakes must stop.