On Tuesday night, after England's victory over Colombia, a friend and I did some calculations on the back of an envelope.
Depending on how we rated their chances against potential future opponents, my friend reckoned Gareth Southgate’s side now have roughly a one-in-five chance of coming out tops at Russia 2018.
I made it more like one-in-16. Either way, the unthinkable is now just about foreseeable. England could, conceivably, win the World Cup.
Is it wrong that this prospect filled both of us with horror? In a word, no. The tradition of Irish sports fans cheering against England is a long established one.
The commentators who query it are often people with a close personal connection to England or very keen sense of the evolving, shared history between the country and Ireland.
What they don't always have is much understanding of sport. I'm not saying historic enmity can't fuel a sporting rivalry. (Just look at the Dutch and the Germans, say, or Real Madrid and Barcelona.) I'm just saying it would be foolish to assume such factors would ever tell the whole story.
Look at what happened, earlier this summer, when former US soccer captain Landon Donovan publicly declared he would be supporting Mexico at this year's World Cup. The former Everton striker was immediately hit by an avalanche of criticism from fans and former team-mates.
No one could argue that the United States grapples with some historic inferiority complex when it comes their southern neighbour. Neither was Trump-era identity politics in play.
Two former USMNT teammates who were among Donovan's harshest critics were Carlos Bocanegra and Herculez Gomez, who are both of Mexican descent.
What these players and fans grasped is something that sporting day-trippers often can't: that pettiness and vindictiveness aren't the regrettable downside of any decent local sporting rival. They're its entire raison d'etre. (With healthy competition and mutual respect, naturally, coming in close behind for those coveted Europa League spots.)
If it weren’t for pettiness and vindictiveness, in other words, we’d all just be yelling at a bunch of strangers kicking a ball around a field. And what would be the point of that?
