Provincial appeal gives Irish sides power to make move overseas
Derby games like Leinster v Munster were never about anyone else but ourselves. It didn't matter if rugby fans in England or Europe were watching because it wasn't about getting their attention or approval; derbies were always about us and how we viewed ourselves.
Who cared what the outside world thought if the score was 3-0 at Thomond Park with a couple of thousand watching, or if the result was 25-6 in front of a record-breaking crowd of 82,208 in a Heineken Cup semi-final at Croke Park. It was always personal between the provinces and that was all that mattered.
The Leinster v Munster games brought out a self-indulgence in the past because we knew we had a rivalry which was better than anything England and France had to offer at the time.
If the movie Batman v Superman was released when the Leinster-Munster rivalry was at its zenith, we would have suckled on the clichéd comparisons of the game as a blockbuster between two superpowers with heroes and villains and enough sub-plots to merit their own spin-off shows.
We didn't need anyone else's attention or approval because Munster and Leinster did not so much seize the moment in Europe as wrestle it to the ground with five titles in seven years. And they indulged us with two unforgettable European semi-finals in 2006 and '09.
The teams had personalities and enforcers which would have made even Eddie Jones whimper with envy. Felipe Contepomi v Ronan O'Gara v Johnny Sexton were match-ups to make your mouth water.
O'Gara wasn't afraid to make England sit up and take notice, either, when he said in an interview that "we've got more talented players than the English in many positions" before Munster played Leicester at Welford Road in a Heineken Cup pool game in 2006; words he backed up with a late, long-range, winning penalty. That's how good Munster were.
Leinster brought it to another level and Irish rugby even had the good grace to share an all-Irish final with Europe in Twickenham in 2012 which further franked a misguided notion that European club rugby revolved around us and our derby games.
But that dominance in Europe petered out. The current Leinster v Munster rivalry almost feels like an artist's impression of the intense high of what existed between the pair in the noughties and the start of this decade.
Both provinces have fallen/been left behind to such an extent that neither got out of their pool in Europe this season and have only the league left to play for, with Munster in a fight to even guarantee their place in next season's Champions Cup.
But besides players and fans, the Leinster-Munster rivalry remains relevant in terms of the provinces' long-term future and how Irish club rugby is viewed by England and Europe.
With the Champions Cup showing that money talks, with the England and French clubs dominating the quarter-finals this season, is the Pro12 really the best option for the provinces?
It's starting to feel like they could out-grow it and hit the glass ceiling sooner rather than later.
The Aviva Stadium will be packed this evening, which makes this derby feel like it's bigger than the Pro12 itself.
This game follows last night's derby between Ulster and Connacht which has got more traction than ever before with Connacht the story of the season.
Irish provinces - Leinster (4), Munster(3) and Ulster (1) have won the league eight times in 14 years and all four provinces are in with a chance of making the semi-finals this season.
So is the Pro12 getting more out of the provinces than the provinces are getting out of the Pro12? Is it time to think about a move to the English Premiership?
The Premiership continues to attract the cash and interest. It's been suggested before that the provinces should look at joining the English league - a view which isn't looking as outlandish as perhaps it once did.
The new TV contract signed last year between the Premiership and BT was reportedly worth far in excess of the £152m agreement the pair signed in 2012.
Last month, Premiership rugby signed a new deal with NBC to become their new media partners in the United States.
Even Toulon president Mourad Boudjellal has stated that he wants in on the Premiership. And it's not hard to imagine Welsh clubs wanting to get into bed with the Premiership at some stage too.
When talks were breaking down around a new European competition two years ago the Welsh regions threatened to join the Premiership if a new European Cup wasn't launched.
You also just need to look at the football model with Swansea City in the Premier League and Cardiff City in the Championship.
The way the Heineken Cup was dismantled underlines that nothing is safe about current structures and the Irish provinces may need to follow the money to remain competitive or to safeguard against being left out in the cold.
If the Welsh decided to jump ship from the Pro12, it would be disastrous for Irish rugby.
Our derby games are not just about us anymore but also about showing the value they bring to a competition.
This evening's game showcases the draw that a Leinster v Munster game still has, not to mention Connacht and Ulster. The power of four has never been so important.