Europe needed a ‘miracle’ to recover from a 10-6 Saturday evening deficit at Medinah in 2012.
What, then, will it take to turn around a 11-5 scoreline at Whistling Straits?
Divine intervention? Astral influence? Deus ex machina?
Whatever it is, Padraig Harrington and his men will take it. The ringing in their ears right now is not the residual din of a raucous home crowd so much as the clanging sound of inevitability.
Stick a fork in it. The 43rd Ryder Cup is as good as done.
No side has ever overturned a deficit of more than four points going into the final day’s play. Europe will have to do so with almost no fans to cheer them on, zero momentum, and the capacity to send out the inspired Jon Rahm only once.
And that's to say nothing of the irrepressible juggernaut that is the US team. Everybody on Steve Stricker's side has won a match. Six Europeans, by grim comparison, have failed to register so much as a half, amongst them cornerstones of recent victories Rory McIlroy, Ian Poulter, Lee Westwood and Paul Casey.
But for world No.1 Rahm and his fellow Spaniard Sergio Garcia, this thing might already be mathematically over.
Instead, the outcome continues to exist in the realm of statistical improbability. The mother of all long shots.
As Butch Harmon put it, a European win would be "the greatest comeback in the history of sport".
Publicly, Harrington maintains it can happen.
"Six points is a tough one to make up tomorrow, but I think we were a half-point short of that in the Miracle at Medinah on Sunday, so we're just going to have to push for that tomorrow," he said.
"They have to just go out there and win their own individual match. There's nothing more they can do than that. They have to focus on that and not look at that bigger picture and focus on their individual self and play their game and win that and then just see how it adds up."
His counterpart Stricker - the man whose loss to Martin Kaymer in 2012 sealed the 'Miracle at Medinah' - is determined that his players don't make the worst kind of history on Sunday.
"I just said that we've got another day," he said. "It's not over yet. Let's not rest on what we've done these first couple of days, and you know, don't be content with where we're at and let's go out there, we want to win the session again tomorrow.
"These guys are still very focused. I think they have learned from our past mistakes, as well. They know. They have watched.
"No-one is taking this day tomorrow for granted at all, and we are totally focused on what we need to do to get the job done."
The margin of the USA's seemingly inexorable victory, of course, will inform how this year's match comes to be remembered.
The 'Shellacking in Sheboygan'?
The 'Ass-Kicking in Kohler'?
The 'Walloping at Whistling'?
The 'Whipping in Wisconsin'?
That's TBC. The destiny of the trophy? Not so much.