The most remarkable thing about Aaron Ramsey's season so far is not simply that he has scored as many goals in three months as he had amassed over the previous six years for Arsenal.
It is not even the variety and the quality with which he adapts his game to Mesut Oezil and feeds off his new German team-mate.
And it is also not what Arsene Wenger says it is - confidence - that has made the 22-year-old Welshman such a potent game-winner.
Take all of those, and there is still one more factor beyond them.
That is that Ramsey lines up in the third tier of Arsenal's attacking formation. He often starts alongside Mikel Arteta or Mathieu Flamini, just in front of the central defenders.
For his match-winning goal in Dortmund on Wednesday, Ramsey had to sprint beyond Santi Cazorla and Tomas Rosicky.
Having been involved in the swift inter-passing that started the momentum, the Welshman kept running straight ahead.
Maybe through all the training they do together in London, Ramsey was thinking three moves ahead.
Maybe he anticipated Oezil chipping the ball from the right towards Olivier Giroud.
And anticipated that Giroud would win the aerial battle and knock the ball down.
Then, the third element of guesswork from the man running from the third tier of Arsenal's team; perhaps Ramsey sensed that the goalkeeper and last defender would dither so that he could nip between them and head the ball across the line.
Is all of that intuition? Is it confidence? Is it practice?
Or is it the inner sense of a player who has just discovered the finishing instinct that is as hidden to view as the homing instinct in a carrier pigeon?
I read a different theory the other day from somebody trying to fathom why Ramsey has hit a streak of 11 goals in 16 Arsenal games (compared to 11 in 150 previously).
The theory was that because Ramsey had broken his leg and feared for his career two seasons ago, he was now a new player - more determined, more aware, more of a glory hunter.
All, or none, of the above might be part of the answer.
But none of it would be happening now if Ramsey did not possess the talent and the physical energy to get himself into striking situations, and if Wenger were not such a good judge, and such a patient manager prepared to spend years nursing the broken Ramsey back to, and beyond, his potential.
Has Oezil played a major part in Ramsey's extraordinary run?
Yes, of course. Oezil's perception to deliver a pass, Giroud's willingness to be the focal point and create for others, Cazorla's incredible eye, Rosicky's touches.
It all helps, it comes from incessant rehearsal, and from the complexity of work ethic and liberty that Wenger coaches.
You think I'm a fan of this? Whatever gives you that impression?
Well, yes, it is another example of Monsieur Wenger's resolve, his belief that the game is not worth playing unless it embraces creativity.
We have seen a better Arsenal side, the "Invincibles" of a decade ago who went an entire season undefeated.
That Wenger collection had the strength and power of Sol Campbell and Patrick Vieira. It had Robert Pires' craft on the wing, Dennis Bergkamp's deft invention, Thierry Henry's great pace and potency.
Ryan Giggs, old enough to have played against that side and still be fit for action, reckons the threat that Arsenal might pose at Old Trafford tonight is not - yet - comparable to those great Gunners'.
But Giggs, now in training to be a coach as well as player, saw the performance in Dortmund.
How could he not admire the discipline with which Arsenal contained Borussia's attacks, then sprung the Ramsey goal in their first attempt after 62 minutes?
Here was something the critics claim Wenger is too much the idealist to bother with - solid defending, sacrificing the flow he so adores to stifle an opponent that had previously not failed to score, or to beat most visiting sides, in almost two years at the cacophonous Westfalenstadion.
Per Mertesacker was towering, and Laurent Koscielny so swift to thwart Dortmund's attacks.
I'm guessing that Wenger is allowing his assistant, the once redoubtable defender Steve Bould, to work on those defenders, and the players in front of them such as Arteta and Flamini.
Finally, isn't it amazing that this current Arsenal momentum of winning 14 and drawing the other of their last 15 away games, has come despite losing Theo Walcott and Alex Oxlade-Chamberlain's greyhound pace on the flanks?
That is where the full-backs, Bacary Sagna and Kieran Gibbs come in with their fast counter-attacks. It's where Oezil and Rosicky find space through improvisation.
And, for the moment while his engine is hot, it's where Ramsey keeps on stealing match-winners.
Wayne Rooney says it's too early to think of Arsenal as successors to the Red Devils for the title. He's right - it is early, but with 10 games gone, Arsenal lead United by five points.
Both clubs know that a win for Arsenal would bolster the Gunners' confidence and might damage beyond repair Man United's defence.
The 2-8 thrashing Arsenal took at Old Trafford two years ago is impossible to imagine again. But Arsenal have not won at Old Trafford since 2006 when United have won eight times and drawn once.
But those, as Wenger mischievously points out, were under Alex Ferguson. Not only has Fergie gone but so too has his Dutch coach Rene Meulensteen, who apparently was decisive in luring Robin van Persie from Arsenal to United.
Van Persie's subdued start to this season could be a consequence. Or it might be that United bought no one in the summer to do what Oezil does for Arsenal.
Ferguson's successor David Moyes says United were offered Oezil but felt that with Rooney and van Persie in the team, the German wasn't worth £42 million (S$84 million).
If Oezil needs extra motivation to add to his two goals and four assists since joining Arsenal eight league games ago, he might just have got it.
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