The trend for those holding home advantage to always come through the PRO12 League semi-finals was maintained last week to leave first seeds Leinster to take on second seeds Connacht on foreign soil.
The laws of natural evolution in this game would imply Connacht have to stomach losing at least one before winning one.
Just look at Leinster and Glasgow.
For example, the former's dominance was delayed by three successive defeats in 2010, 2011 and 2012 before they finally got it right in 2013 and 2014.
Leinster coach Leo Cullen has had to make a late change in promoting Ross Molony for the absent Devin Toner.
It remains to be seen how unsettling this will be as their lineout lynchpin is replaced by a 22 year-old Academy option with Hayden Triggs coming onto the bench.
However, Molony has worn 20 caps for Leinster this season, a dozen coming from the start, and has impressed those inside the camp with his leadership skills.
Club captain Isa Nacewa has not been able to prove his fitness from an arm injury.
Just as well Rob Kearney has finally been able to master his misfortune to return to the No 15 shirt in what is the second change from that commanding defeat of Ulster last week.
Connacht will aim to skip all the play-off pain to scream through from seventh place last season to become the fifth different club to claim the trophy since the play-offs kicked-off back in 2010.
It is so difficult to make a case for Connacht on paper; much easier on their play and their consistent form as the only club to stay in to Top-4 from the end of Round 1 to the conclusion of the regular season.
Okay, they had the important advantage of losing fewer players to the World Cup and the Six Nations than the main clubs from the Celtic Nations.
When the powerhouses were restored to their full complements, Connacht managed to hang in there and confirmed their newly earned status with back-to-back wins over the holders Glasgow.
There is a rhythm to their game which Leinster have rarely found this season.
The heartbeat has come from Bundee Aki, the grit from the front five, led by Aly Muldowney, and their execution from the coaching ticket.
At this point, Connacht only know one way. They have to keep the ball and probe for the openings.
Leinster have to avoid what Glasgow did in falling into the trap of becoming impatient enough to lose their discipline.
They have the experience to keep their patience and make it three PRO12 titles in four years.
Leinster: R Kearney; D Kearney, G Ringrose, B Te'o, L Fitzgerald; J Sexton, E Reddan; J McGrath, R Strauss, M Ross, R Molony, M Kearney, R Ruddock, J Murphy, J Heaslip (capt).
Connacht: T O'Halloran; N Adeolokun, R Henshaw, B Aki, M Healy; AJ McGinty, K Marmion; R Loughney, T McCartney, F Bealham, U Dillane, A Muldowney, E McKeon, J Heenan, J Muldoon (capt).