Ange Postecoglou’s unusual career encompasses a period around 2007 when Tottenham’s new upwardly mobile manager was out of work and beginning to wonder if he would ever be delivered from what he described as a “coaching wilderness”.

It came at a time when Australian domestic football was enjoying a fresh lease of life with the launch of the then eight-team A-League, none of which had appointed Postecoglou. He had won the title twice as a manager with South Melbourne Hellas in the old days of Australia’s National Soccer League but that seemed to count for little.

The manager who will lead an unbeaten Spurs side in the North London derby at Arsenal on Sunday, was, as he recalls in his 2016 autobiography, coaching school children and amateurs in Melbourne parks in order to stay occupied. He was not a rookie enthusiast – he had won Australian titles as a manager and a player and coached the country’s junior teams. He never doubted he would succeed eventually, but, in his own words, did, over those 13 months, “occasionally indulge in melancholic questioning of what I was to do from there.”

Postecoglou’s autobiography, written when he was Australia coach, is a thoughtful treatise on the game’s development in that country as well as his own life. He only got the A-League job at Brisbane Roar because their coach Frank Farina, a former Australia international, and briefly of Notts County, was charged with drink driving. The club had to sack Farina and Postecoglou’s effect on the team’s fortunes was so remarkable that he never looked back – in Australia at least.

Fourteen years on and Spurs stumbled across Postecoglou after Julian Nagelsmann and Arne Slot had turned them down and they had interviewed Luis Enrique. Despite his success at Celtic, Postecoglou might never have got a Spurs interview, were it not for his agent Frank Trimboli, who is one of the big players in that business. Chelsea had briefly considered him when it came to their most recent appointment, but he was never interviewed. Crystal Palace also took note before reappointing Roy Hodgson.

Daniel Levy sounded very glad this week to be addressing a Spurs fans forum with most of them currently becalmed, but the Spurs chairman would never have envisaged appointing Postecoglou, who did not figure on any of the early shortlists.

In keeping with his policy of disarming honesty, Postecoglou has never tried to hide that. Indeed, he happily declared he was “last man standing” for both Celtic and Spurs jobs in a BBC interview this week. Watching that one was reminded of the excruciating efforts of the Football Association back in 2006 to repeat through gritted teeth the mantra that Steve McClaren was their first choice as England manager. The world knew that was not the case.

The Postecoglou era at Spurs is still in its early days. Indeed, given Spurs’ record at the Emirates, Sunday could be chastening or it could be another giant leap forward. The sense of hope engendered by the new manager, however, is durable enough to take the former. Either way, Postecoglou’s arrival once again opens up the question of what a good appointment looks like and how one talent-spots coaches and managers.

A 58-year-old with a track record in Australia, Japan and Scotland feels like a gamble but as ever it is more about the individual and what they have done with the opportunities they have been afforded. A similar story with Graham Potter, and then his successor at Brighton, Roberto De Zerbi. Both of them had relatively low-key careers before their Premier League opportunities but Brighton judged them not on the size of the clubs they managed but what they had done with the resources available. What happened to Potter at Chelsea feels less a reflection of his capabilities given what has followed there.

What could others learn? At Manchester City one presumes the succession plan for Pep Guardiola is being approached with a similar intensity that one might expect of the formulation of governmental fiscal policy. And why not? There is no decision more important for any club. It would be dangerous to assume that someone suitable might just be available when the moment comes.

Clubs want a collegiate approach and a manager who can work with their recruitment strategy. They want someone who will not blame others at the first sign of trouble. They need a manager who can work with the multi-million corporate entities also known as footballers, which is not to say that those same footballers can be endlessly indulged. Establishing the manager’s power has always been difficult, in whatever era he found himself. They also need a good coach.

The current coaching era has its fair share of former famous players but increasingly there are those who come from a very different profile: Jurgen Klopp, De Zerbi, Steve Cooper, Unai Emery, Thomas Frank, Hodgson, Eddie Howe, Erik ten Hag and Postecoglou as well. All of them have been distinguished by a degree of struggle – or at least the sense that there was something about them that might be a disqualifying factor when it came to the very elite end of the game.

There is a point in all these managers’ careers when figuratively they crest that hill, and the game – its chairmen, chief execs, and the media and fans – view them differently. It is an unspoken criteria, but it exists. The hardest thing to do is spot ability early. Curiously, Guardiola, for all his astonishing success, had the same thing. As a famous former player he backed the wrong candidate in the 2003 elections for Barcelona president and consequently wondered if he would ever work at the club.

His former team-mate Txiki Begiristain, who had backed the winner Joan Laporta and got the sporting director job as a consequence, eventually gave Guardiola the Barca B job anyway. Given their enduring partnership it was surely the best decision Begiristain ever made. Which did not make it the obvious one at the time.