This is the fifth season of the format whereby the PRO12 league season-proper is followed by play-offs in which first host fourth while third travel to second in the semi-finals.
Never since its inception have the club finishing fourth managed to beat those who were first. Nor have those who were second ever lost a play-off semi-final to opponents who were a rung beneath them at the end of the round robin league-stage fixtures.
So if Ulster are to win this season's title, they are going to have to create history.
As things stand, Leinster and Glasgow Warriors lie first and second with one game to go. Both are at home this weekend, against Edinburgh and Zebre respectively.
It would be a major upset if the outcome in either case was anything other than a home win, which means the semi-finals on May 16/17 almost certainly will be Leinster v Ulster and Glasgow v Munster.
Yet despite all of what history may suggest, fourth-placed Ulster may just view a trip to the RDS home of last season's champions and this term's table-toppers as being preferable to having to go to either Glasgow or Munster in the semi-finals.
That is understandable, for Ulster have not won a PRO12 match in Glasgow since March 2011, while January 2009 is the last occasion on which they managed an away-day league victory over Munster, albeit that they recorded Heineken Cup victories over both – in April 2012 at Thomond Park and in October of the same year at Scotstoun.
But Mark Anscombe's men beat Leinster at the RDS on March 30, 2013, thereby completing a home and away PRO12 double. And had they produced a better opening 10 minutes and been a little more accurate later in the match, Ulster might very well have emerged triumphant from the same stadium eight weeks later when the sides clashed in the PRO12 final.
Instead that meeting finished 24-18 in Leinster's favour, which meant that for the third time in three seasons they had beaten Ulster in a crucial one-off fixture, the other occasions being the 2010-11 PRO12 semi-final (18-3) followed by the 2011-12 Heineken Cup shoot-out at Twickenham (42-14).
Ulster supporters' conviction that their team can win a Dublin semi-final grew on Friday night when, with 14 men, they restricted full-strength Leinster to a hard-earned 22-20 win at Ravenhill, an occasion which marked the Belfast curtain calls of both home captain Johann Muller and Leinster and Ireland legend Brian O'Driscoll.
But following the match in which home loose-head Tom Court was dismissed after 16 minutes for a tip-tackle on Ireland lock Devin Toner, Ulster coach Anscombe warned against reading too much into that particular display.
"They're a quality team and it's very easy to get drawn into thinking that we were a man down so if we played them with 15 we'd get it right," he said.
"But they're not leading this competition through luck. Not only do they have internationals in most positions, they've got internationals on the bench in most positions so that shows their depth."
He expressed concern, too, about Ulster's concession of penalties. Ian Madigan fluffed four which, had he kicked them, would have seen a very different final score.
"Our discipline was poor at times and we gave away too many penalties," Anscombe said. "Our clean-out and our attention to detail at the breakdown was pretty average too.
"So if we're going to progress – no matter who it's against – we've got to get those areas sorted out pretty quickly."
In addition, unlike a great number of Ulster fans, he was not outraged by referee Luke Pearce's decision to dismiss Court.
"The fact is if you lift someone up you're putting yourself in that position, aren't you?" was his rationale.
He added: "We're proud after what happened that we fought through and came out with a bonus point; I'll take that with 14 men against Leinster any time.
"But we've got to fix things if we want to progress in the play-offs, because we have many times shown the characteristics of the individual – what we've got to show is that we've got the smarts in our decision making and the accuracy in our game to complement that. If we get those two or three things together, we'll be a tough team to beat."
As for the prospects of some of his injured stars being available for the semi-final, he said: "It gives another week to the likes of Ruan (Pienaar), Rory (Best) and John Afoa."