The British and Irish Lions have been crunching the numbers all week in an effort to make this tour add up to something more than yet another lost opportunity, but if they finish on the wrong side of the scoreboard arithmetic today, one number in particular – the unluckiest number of all, according to the superstitious – will surely come back to haunt them. No Brian O'Driscoll in the red 13 shirt? It seems a hell of a call, even now.
"That was Wednesday's news: we've moved on." So said the tourists' scrum coach Graham Rowntree yesterday in a determined effort to put the story to bed.
He would have been happier talking about different figures entirely: the ones revealing that the Wallabies have lost five of the last six matches staged at the huge Olympic Stadium on the edge of town; that the Lions have won nine of their Tests in this city while their hosts have prevailed on only four occasions; that the men from the British Isles have nailed three-quarters of the international games they have played on Australian territory since 1899.
He might even have pointed to his pack's "officially ratified" 93% success rate at the line-out in Melbourne last weekend had that particular calculation not flown directly in the face of reality and confirmed the old saying about lies, damned lies and statistics.
The Lions are still vulnerable in this crucial area – quite why they feel they can do without the ultra-reliable athleticism of Tom Croft for the second Test running is a mystery that passeth all understanding – and if the possession they obtain today is as unusable as it was seven days ago, the precise make-up of the midfield will border on the irrelevant. They could field Darth Vader and Gandalf at 12 and 13 and still lose.
The Wallabies finished much the stronger in both previous Tests and have convinced themselves that if the decider is played at a high tempo, they will be the ones to benefit.
Will Genia rammed the point home when he made a somewhat unfavourable comparison between the Lions and the world champions of New Zealand. "When you play the All Blacks, it's really fast: everything is speeded up, there are no stoppages, you can't catch your breath," the Wallaby half-back remarked.
"The Lions enjoy the physical side of things. They like to play stop-start, get ascendancy at the set-piece and take three points wherever they can." Ouch.
The tourists have been wondering aloud whether the Australians can possibly revisit the emotional heights they scaled in Melbourne.
As for the lessons of the past, they are not especially reassuring from the visitors' perspective. Only twice in 120-odd years have the Lions claimed a series victory in the southern hemisphere by winning the final Test.
If the Lions lose, as the bookmakers now expect them to do, we can expect the affair to rumble on, deep into the new season and possibly beyond.
But games of this magnitude are rarely, if ever, decided in the No 13 channel. The numbers that really count are to be found elsewhere.