Ah, the 'granny rule', the cheat code of choice for generations of Ireland squads.
When the pool of talent coming out of Ireland dries up, our diaspora is there to supply us with players who may have only slight attachments to Ireland.
Once, Jack Charlton went to watch Oxford United in order to scout their star striker, the Irish-eligible John Aldridge. Impressed by the striker's traits, Charlton managed to convince Aldridge that his future lay with Ireland. However, Charlton was also suitably impressed with Oxford's diminutive midfielder, Ray Houghton. With no idea of Houghton's Irish credentials, and only the knowledge that Houghton had been born in Glasgow, Charlton plucked up the courage to ask him if he had an Irish in him.
The rest is history.
This story must have been ringing in Shane Long's ears on Tuesday evening during their Carabao Cup tie against Manchester City. The Tipperary native with 82 Ireland caps showcased a future in scouting after his post-match conversation with City debutant, Tommy Doyle.
Speaking to Man City's YouTube channel, Doyle mentioned his conversation with Long after the game, with Long asking the midfielder did he have any Irish in him.
At the end, Shane Long came up to me and he said 'do you have any Irish in you?' Obviously, because of my last name, Doyle.
To hear that from someone who's been around the game a massive time, and got a load of international caps for Ireland, it does mean something to me.
Unfortunately, it doesn't seem like Doyle is eligible to play for Ireland.
He comes from a line of Manchester City legends, with both paternal and maternal grandfathers playing for the Citizens. Mike Doyle, his paternal grandfather, also made five appearances for England in the late 1970s and was a long-time teammate of Glyn Pardoe, Tommy's other grandfather.