The Under-21 hurling championship remains true to the antique format that prevailed in the senior ranks until the year of our lord, 1996.
For decades, they were welded to the same province based structure that applied in Gaelic football as if it were mandated by God, when hurling geography cried out for a bespoke model.
It was the following year - 1997 - that the back door was nudged open for the first time as losing provincial finalists were allowed back into the All-Ireland quarter-finals.
Through all this, the U21 championship has witnessed zero experimentation in the matter of formats and there has been little demand to see more games at the grade.
Meanwhile, the Leinster counties are still stubbornly refusing to allow Galway's traditionally formidable underage teams enter the province.
And so the Galway U21 hurlers retain that old air of an exotic unknown quantity, arriving untested in August to face the Munster or Leinster champions.
A highly fancied Limerick team won the Munster championship in fine style, demolishing both Tipperary and Clare and squeezing past Cork in a low-scoring final in the Gaelic Grounds.
Their opponents Galway make their championship debut at the weekend.
The standard rule of thumb in assessing U21 teams is to peruse the minor championship results from three years earlier.
Last year, Waterford strolled past Galway in the U21 decider in Thurles, essentially a repeat of what occurred in the 2013 minor final.
And three years ago, Limerick slaughtered Galway 1-27 to 2-09 in the All-Ireland semi-final in Croke Park.
LIMERICK
Nine of the Limerick starting line-up that day are in the team for Saturday evening's game. The most celebrated among them are already being depended upon at senior level.
Inside forward Peter Casey won an U21 title two years ago, coming off the bench to land 0-03 as Limerick cruised past Wexford.
This year, he was probably Limerick's most lively forward in their three-point defeat to Kilkenny in Nowlan Park.
The well-established Cian Lynch, meanwhile, has been a fixture of the Limerick senior team for the past three seasons, earning the Man of the Match award on his championship debut against Clare in 2015.
Sean Finn slotted in at corner-back for the seniors this year, while Barry Nash, Tom Morrissey and Aaron Gillane made cameo appearances.
Chief free-taker Gillane set the world alight against Clare in the Munster semi-final, hitting eight points from play, while Morrissey hit 1-04 and took home the Man of the Match gong against Tipperary.
Their thrilling attack racked up scores of 4-24 and 1-28 against Tipp and Clare respectively and while they were reasonably well-stymied by a dogged Cork team in the provincial decider, they remain heavy favourites to reach the All-Ireland final.
GALWAY
Galway have an illustrious modern history at this age-grade but their last title dates back to 2011, when Anthony Cunningham's team sauntered past Dublin and over-excited Man of the Match Davy Glennon had to apologise for an expletive in the post-match interview.
This year's U21 crop are considerably less heralded than their opponents though the history of this grade is littered with examples of little-known Galway sides upsetting fancied opponents in the All-Ireland semi-final.
Their starting XV on Saturday evening contains four members of the senior squad which attempts to bridge a 29-year gap next month.
Conor Whelan hit both of Galway's goals in their 15-point defeat to Limerick in that minor semi-final from three years ago.
At 19, he was torpedoed into the senior side before the 2015 All-Ireland quarter-final against Cork and hasn't been out of the team since.
As of now, he is a contender for senior hurler of the year, currently fourth favoured in the bookies' standings.
As for the other three members of the senior panel who feature this weekend, none are regular starters on Micheal Donoghue's team, with only Craughwell's Thomas Monaghan being sprung regularly from the bench.
Wing back Sean Loftus captained Galway to their most recent All-Ireland minor title in 2015 and is currently part of the senior squad.
Jack Grealish, Brian Concannon and Jack Coyne all featured prominently in the 2015 minor final victory over Tipperary and have graduated to the U21 starting lineup in time for Saturday's meeting.
KILKENNY
In a year when their seniors finally appeared to succumb to their long anticipated decline and absented themselves from the business end of the championship, Kilkenny have returned to prominence at the U21 grade.
Kilkenny haven't won an U21 title since 2008 - a factor which explains their current malaise at senior level - and haven't appeared in an All-Ireland final since 2012.
However, this current crop have pedigree, with this age-group responsible for claiming the All-Ireland minor title in 2014.
Unsurprisingly, they are unbackable favourites to reach the U21 All-Ireland final this year.
As if to prove the worth of the three year rule of thumb, it was Limerick who Kilkenny pipped in the final in a result which confounded bookies expectations.
Nine of those that started the 2014 All-Ireland minor final were on the starting team in the recent Leinster final against Wexford.
Darren Brennan, Tommy Walsh, Conor Delaney, Pat Lyng, Jason Cleere, Luke Scanlon, Sean Morrissey, Alan Murphy and Liam Blanchfield all started both the 2014 All-Ireland minor final and the recent U21 Leinster final.
The star of the show against Wexford in Nowlan Park did not feature on the 2014 All-Ireland winning team.
Richie Leahy hit 0-06 from play and was awarded Man of the Match in the Leinster decider. He was after rewarded with a call-up to the senior squad for the qualifier against Waterford.
Cody has been reticent about throwing U21 players into the mix with Blanchfield and Leahy being drafted into the senior ranks in 2017.
DERRY
Derry bridged a nine-year gap to their last Ulster title at this grade with a handsome 14-point win over Down in the provincial final.
It was their two-point semi-final win over Antrim - winners of the previous eight Ulster titles at this level - that teed them up for this long-awaited victory.
Unsurprisingly, Slaughtneil players are prominent in the side. Dual star Cormac O'Doherty hit 2-05 of their 2-11 tally against Antrim.
Manager Collie McGurk - a former dual inter-county player who was part of the 1993 All-Ireland winning squad - has sought to infuse his players with a fearless physicality.
