It’s an often quoted formula.
If x happened then y could have been z.
Revisionism helps us understand and appreciate the chaotic reality of football, the history of which is just one extended series of Sliding Doors moments.
And Marco Reus, a modern tragic hero of the sport, has been the subject of such conversations enough already.
What if he joined Real Madrid?
What if he wasn’t so injury prone?
And now, what if he became a No10 sooner?
Dortmund’s title charge is fuelled by youthful exuberance with Jadon Sancho, Achraf Hakimi, Abdou Diallo, Jacob Bruun Larsen, Christian Pulisic and a handful more under-23s contributing to a six-point at this stage of the season.
But at the centre of it all, quite literally, is Reus.
Having previously played most his football out wide, the 29-year-old has occupied the role of creator-in-chief just ahead of the Axel Witsel-Thomas Delaney double pivot for the majority of the current campaign.
18 league fixtures have procured 12 goals and six assists, a return that has put him among the early favourites for Player of the Year in Germany alongside the likes of Thorgan Hazard, Robert Lewandowski and Frankfurt’s Sebastien Haller.
Reus has hardly been wasted out wide, far from it.
However, this season he’s shown the benefit of his increased involvement in Dortmund’s attacking play and we can’t help but wonder what would have happened had his reinvention as a No10 occurred earlier in his career.
Reus was a Borussia Monchengladbach player when Jurgen Klopp’s Dortmund won back-to-back titles in the early 2010s.
This season represents his best chance to win what would be just the second major honour of his career.
The overriding caveat under Reus’ career is his torrid injury history.
At 29 years old he has just 37 caps for Germany, a criminally low return for a player of such talent.
Die Mannschaft’s hero of 2014, Mario Gotze, famously held up a shirt with Reus’ name printed on the back during the aftermath of the final in Brazil.
Two years later on the eve of Euro 2016, injury once again forced him to watch a major tournament from the comfort of his sofa.
A more durable body would not only have gifted Reus a World Cup winners medal, he could have been the standout golden boy of German football.
Imagine a fully fit Reus as a No10 from the age of 21 — what would Mesut Ozil’s fate have been then?
Ozil was named the national team’s Player of the Year five times out of six between 2011-2016.
Such dominance is particularly impressive when you consider the competition: Philipp Lahm, Bastian Schweinsteiger, Toni Kroos, Thomas Muller, Manuel Neuer, etc…
The Arsenal playmaker was made a scapegoat for Germany’s failure in 2018 and the toxic fallout may have triggered a premature international retirement.
But for years, he was the poster boy of a talented side — a fate that cruelly alluded Reus.
In a not too different alternate reality, Reus has 100 caps for Germany, a World Cup medal, and iconic status as one of Europe’s finest No10s.
While the frustration of his injury problems may never evaporate fully, he has time yet to build a warranted legacy.
Captaining Dortmund to a league title would be a phenomenal start.
And with Ozil out of the international picture, he could finally cement himself as Germany’s No10 for the next major tournament and beyond.
And bloody hell, he deserves it.