This will go down as one of the most baffling decisions in Australian football history. Sadly it may well overshadow his legacy of Asian Cup glory, the regeneration of the Socceroos side and its philosophy, and their stand out performances against some of the biggest names in world football.

Already the conspiracy theories have gone into overdrive - did the FFA combine with Fox Sports to drive him out to make way for Graham Arnold to take over? The suggestion is utterly bizarre - if the FFA wanted Arnie in, they just sack Ange and install Arnie rather than try to undermine the coach and make him fail in WC qualification.

Apart from anything, the FFA needs the cash from the World Cup to balance their books. Financially alone, they had to back Ange to qualify.

But there is without doubt behind the scenes tension between Ange and the FFA. By all accounts, he was still fuming over the slapdown when the FFA made him eat his words over supporting players in their wage dispute in 2015.

His autobiography released last year was choc-a-bloc with flashpoints that went against FFA policy too - supporting promotion-relegation and A-League expansion among others which directly contradicted the FFA.

But Ange brought much of the most recent pressure upon himself.

The switch to the back three last March was a key football moment in his reign. Introduced at the last moment, away from home with only 24 hours to prepare the players, was impetuous and flawed.

The subsequent transition period where players got used to the new formation and Ange tried to find the best combination of players ultimately cost us automatic qualification.

And for what? Ange had ALREADY revolutionised his squad. He had ALREADY found his best XI and his best tactics. And now a new coach will tear it all down anyway...

Before March we looked good, although still capable of improvement. After March, with the exception of the Confeds Cup game against a weary Chile, we were constantly shaky at the back until pretty much the final game where it came good.

In football terms, the change meant we overloaded midifield and attack to create more scoring opportunities for our lone striker. Ange had correctly identified that, Cahill aside, our strikers need more chances to convert into goals because, frankly, our strike rate in front of goal was poor.

By creating more chances, there was, obviously, more chance of actually finding the back of the net. Even with that though, we still struggled to score.

The compromise was that our defence was made substantially weaker, and Ange's selection in that back three weakened it further.

Unless, like Chelsea, you have absolutely world class fullbacks available to you to convert into centrebacks, who are well-drilled in a back three formation through training time you can only get at club level, you really need three specialist centrebacks.

Ange toyed witha mix of fullbacks and centreback-slash-fullbacks, and relied on wingbacks with dubious defensive credentials to fill out part-time defensive duties on the flanks.

In the eight months since, Mathew Leckie especially has grown into his defensive role but initially it was an anathema to him. Behich is a dynamo on the opposite side, upfront and in defence...but it took us many games to get there.

Jurman and Sainsbury are now the core of the back line and while Bailey Wright fills out the three, we're still searching for the final piece of that jigsaw.

And for all the insane number of chances we're creating upfront, we're still struggling to score. All three goals against Honduras came from set pieces – and we still conceded.

There lay the problem – we weakened our defence, but still were not scoring any more goals...

And now we're here – qualifying for the World Cup by the longest possible route...and as soon as we do, Ange quits, after a month of will he-won't he speculation and debate.

For the past year, Ange has been nurturing a them-and-us mentality between himself and the media. He initially encouraged us to talk tactics with him but then when we started to disagree with him, he wasn't interested.

I like and respect Ange a huge amount, but the job has changed him. In 2013/14, he was approachable, humble and friendly. For the last year, he's... not.

It could be the media brought that on itself, or it could be a change of attitude...but current Ange comes off as the opposite of what he once was.

Stubborness and self-belief are essential for coaches but so also is knowing when to be dogmatic and when to be pragmatic. Pragmatic doesn't have to mean parking the bus – it can be just working with the best tactics to suit the players currently available...and even just admitting you've got something wrong.

The media pressure on Ange became intense after news of his exit was leaked. If Ange did not want that leaked, he simply shouldn't have told ANYONE about it until after the final game.

Maybe he's tired. Club football will be more tiring. Maybe he wants a new challenge. The World Cup would have surely provided that though. Maybe he misses week-in, week-out football. Maybe he was sick of the FFA hierarchy - but they could all be out of a job by next week.

Or maybe he was determined never to be browbeaten out of a job again like he was by Craig Foster when he was Joeys coach all those years ago – and was determined this time to leave on his own terms?

But if he thinks the media pressure is tough in Australia, he's got a shock coming for him if he ever lands up in a high profile job in a country that is more football-focused than us.

A new coach will now come in and rip up Ange's tactics and do things his own way. So what was the point of the switch to the back three?

In qualifying, Ange only lost two games which is a fantastic record. That, though, was not the problem. The problem was the games we should have won – but drew, and even the games we did win but didn't keep a clean sheet which ultimately cost us automatic qualification on goal difference.

We could have wrapped up qualifying much earlier in the campaign if it hadn't been for the draws in a few games and where we copped soft goals, late goals and goals which exposed our self-imposed defensive frailties.

For the third time in four World Cups, a new coach will have at most seven games to make his mark on the Socceroos before the tournament starts, probably less. Someone like Arnie will beef up that backline to a more conventional back four, probably with Milligan and Jedi screening, with a 1-2-1 attack. 

It will be robust and conventional. It will probably hammer out more draws and snare the odd win while losing by a slim margin to top teams.

Gone will be the style and glamour Ange brought. Gone will be his unpredictability, his innovation, his belief in youth and willingness to make sacrifices now for rewards further down the line.

I don't know about you, but that's not what I wanted. I just wanted him to listen, talk to us more, play three quality centrebacks in the back three if he insisted on doing that, or develop the gameplan that had got him victory in the Asian Cup and that let us dominate in early stages of World Cup qualification.

I can't say enough how disappointed I am in Ange for quitting. I can't believe he can truly see himself watching Australia play in Russia without him on the bench. Very, VERY few coaches ever get to take their national teams to two World Cups in a row.

I think he'll regret this decision.

The best was yet to come. With a weak World Cup missing Italy, Holland and Chile, there is literally no telling how far we could have gone in Russia under Ange if we land a favourable group stage.

I miss him already – but I suspect it will be nothing compared to how much Ange will miss his chance to shine on football's biggest stage.

Thanks Ange. I'm sorry it came to this.