The fundamental difference between Jose Mourinho and Pep Guardiola comes down to philosophy.
Guardiola trusts his players implicitly with the ball.
Mourinho trusts his without.
The arch rivals have a lot in common.
Both are serial winners and they share the traits of the successful.
Both have sizeable egos.
Guardiola may not describe himself as the ‘Special One’ but has cooperated with the writing of several books detailing his success and was a willing participant in the Amazon documentary that catalogued Manchester City’s record-breaking Premier League triumph last season.
Not the actions of a shrinking violet.
And whereas Mourinho is derided for his three-finger salutes or demands for respect for his decorated career, the Twitter account managed by Guardiola’s backroom staff - Pep Team - for a long time had pinned to the top of its timeline the list of trophies he’d won before he clinched his first at City last season.
In short, neither man is slow to remind you of their remarkable achievements.
The similarities go on.
Both are ultimate authoritarians. A challenge to their power tends to end up with one result - be it Bayern Munich’s long-standing doctor Hans-Wilhelm Muller-Wohlfahrt or Eva Carneiro at Chelsea.
They can command unwavering loyalty from one player, and utter contempt from another.
All part and parcel of operating at the highest echelons of the game - and that both men have continued at such levels on their own terms is all the justification required of their methods.
Which is why Mourinho’s about turn at Manchester United in recent months seems so significant.
You might not have noticed, but the 55-year-old has changed.
Guardiola is so dogmatic about his approach to football that he was prepared to let his City career end in failure, rather than alter his philosophy.
Yes, he is in the privileged position of being able to spend in the region of half a billion pounds to assemble a squad capable realising his vision. But his first season in English football was evidence of his determination to stubbornly stick to his principles - even with players too old or patently unequipped to play the football that swept aside all comers last term.
While Mourinho’s ‘Park the bus’ reputation is overblown - and considered a downright insult by players who achieved such success under him - it is impossible to suggest pragmatism doesn’t win out over romance where he is concerned.
Whereas Guardiola actively encourages players to take risks - to beat a man, to want the ball in tight spaces - Mourinho’s game is to remove that element of risk.
It’s all about shape, getting behind the ball, limiting space and avoiding mistakes.
Contrary to popular belief, Guardiola is every bit as obsessed with defending as Mourinho - he just does it higher up the pitch.
The further away the opposition are to City’s goal, the safer he feels.
Mourinho, meanwhile, has always been comfortable inviting pressure on, believing his defensive drills and organisation can limit even the most potent of attacks.
He finds a beauty in that in the way any craftsman would enjoy their art. The trouble is, that appreciation is not shared by a generation brought up on Fifa or watching Lionel Messi and Cristiano Ronaldo score hat-tricks as easily as they breathe air.
It’s not been appreciated by United fans spoilt by Sir Alex Ferguson’s swashbuckling teams or global television audiences left with their heads banging after watching Jurgen Klopp’s heavy metal football.
Crucially, it just won’t do when Guardiola is producing magic week in, week out on the other side of town.
And so Mourinho has been at his most open in recent days about his attempts to release the shackles.
He may be talking about it now, but it is a process that has been ongoing since the start of the summer.
Those who blindly criticised United’s prosaic football ignored the make up of his teams during their troubled start to the campaign, which were decidedly Guardiola-esque.
It’s been common this season for Mourinho to name as many as five attacking players in his front six.
With full backs Luke Shaw, Ashley Young and Antonio Valencia also encouraged to push high up the pitch, it has been a world away from the negative mindset Mourinho adopted in big games during his first two seasons at Old Trafford.
Gary Neville described it as ‘reckless’ ahead of the visit to Chelsea last month when only an injury time goal from Ross Barkley robbed United of a first win at Stamford Bridge since Ferguson’s retirement.
It was a very un-Mourinho way to blow the points - and United’s defensive resolve has been the biggest victim of their manager’s reinvention.
He admitted as much for the first time when conceding his side were lucky not to be five goals down in the 2-1 win against Bournemouth last weekend.
Such frankness was well received by United fans, who appreciated their manager’s attempts to provide them with thrills they’ve been crying out for.
If it was a PR move, it was perfectly executed - particularly coming ahead of a potentially season-defining week, with trips to the champions of Italy and England.
Cynics might say it was a populist move to buy himself time, but another comeback win against Juventus was not the result of a lack of ambition, no matter how late the goals came in Turin.
United also rode their luck. Juve hit the woodwork twice and were denied by two wonderful saves from David de Gea.
Yet Mourinho’s determination to alter his style was emphasised by his admission that he believes a defence-first strategy is still an effective way to win titles in the era of Guardiola.
“Oh yes it is, oh yes it is,” he said. “And you have many examples of teams that do that. You have many, many examples.
“I just think that (attacking football) is the way to develop the team in a certain direction we want to try to go.”
On Sunday, against City’s terrifying forward line, the ‘New’ Mourinho will face the severest test of his resolve.
But so will United fans who have peddled the rhetoric of ‘just wanting good football’.
In reality fans want winning football - that’s good.
How they react should United be on the end of a heavy defeat will make fascinating viewing compared to, say, the 0-0 bore draw of two seasons ago.
Mourinho, however, delivered a bold assertion of what supporters can expect.
Emboldened by performances at Chelsea and Juve, he said: “We want to go to every stadium, and it doesn't matter the team, and we play.
“Then if they are better than us they win. If they have more potential than us, they win. If we make mistakes and pay for the mistakes we lose, but I want the feeling, it doesn't matter where we go, we go to compete and this is the feeling the Manchester United supporters around the world want to have.
“That feeling of switch on the television and it doesn't matter where we play, they know we are going to compete. We will lose matches, but that feeling of we go to play, we go to try to win.”
The re-imagination of Jose Mourinho will make intriguing viewing, whether the football is entertaining or not.
