A standard rule of thumb when assessing the quality of U21 teams is to rewind three years and examine how the minor championship went.
Sure enough, the two teams who contested the 2014 All-Ireland minor final meet in this year's U21 decider.
Limerick and Kilkenny, boasting many of the same players who contested the 2014 minor final, face off in Semple Stadium on Saturday evening.
Neither side had a good 2017 at senior level. Kilkenny's imperial phase finally came to an end this year, while Limerick lost both their matches and departed the championship earlier than any other Tier 1 hurling county.
However, their U21 teams have looked like All-Ireland finalists from a long way out and it's a job to establish which one has been more impressive.
Kilkenny, famously beaten by Westmeath at this level last year, came through Leinster, disposing of Wexford handily in the Leinster final.
Sadly, there isn't an adjective in the English language that could do descriptive justice to the beating they gave Derry in the All-Ireland semi-final last month. After the 52-point win, manager Eddie Brennan had to remind tut-tutting reporters that it wasn't his job to worry about Derry hurling.
Limerick's route to the final was rather more arduous. They demolished both Tipperary and Clare before squeezing by a dogged Cork side in a low-scoring provincial decider.
Three years ago, the Limerick minors destroyed Galway in an All-Ireland minor semi-final - a year after a hawkeye cock-up cost them dearly against the same opposition. Perhaps as a result, they were nearly unbackable favourites to beat Galway in the semi-final.
In the end, they trailed by two points during the final 20 minutes and needed a late spurt to claim a four-point win in an enthralling game.
Limerick enter the final as favourites as they did the minor decider in Croker three years ago. The bookies were confounded then, with Kilkenny winning an entertaining game on a scoreline of 2-17 to 0-19.
How closely do the teams this weekend resemble the minor sides of 2014?
Kilkenny attacker John Walsh was the central figure in that final. A substitute for most of the season, he made the most of a rare start, hitting 2-05 and winning the match.
Walsh has fulfilled the impact sub role once more this year, coming on in the second half against Wexford and Derry, scoring 1-03 against the latter.
Otherwise, nine of those who started the 2014 minor final were on the starting XV when Kilkenny demolished Wexford in the Leinster final.
Goalkeeper Darren Brennan, defenders Tommy Walsh, Conor Delaney, Pat Lyng and the influential Jason Cleere, midfielder Luke Scanlon, and attackers Alan Murphy, Liam Blanchfield and Sean Morrissey are the veterans of the 2014 success who've garnered regular starting spots on Eddie Brennan's side.
Billy Ryan and Richie Leahy, subs in 2014, have graduated to the starting line-up, with the latter attracting the notice of the demanding Brian Cody. He was introduced late in normal time during the Waterford-Kilkenny senior qualifier, hitting 0-02.
Like Kilkenny, Limerick boast nine starters from the 2014 minor final. Unlike Kilkenny, the pick of that crop are already being depended upon at senior level.
From the 2014 minor final, Eoghan McNamara, Sean Finn, Ronan Lynch, Tom Morrissey, Cian Lynch, Peter Casey, Barry Nash, Robbie Hanley and Colin Ryan started the semi-final victory over Galway last month.
Despite entering the game as big outsiders, Kilkenny started brightly and had nosed ahead at half-time by 0-12 to 0-10. Of the starting line-up that meet on Saturday evening, Alan Murphy popped the frees while Liam Blanchfield and Luke Scanlon stroked over points from play.
This lead was stretched out to four points early in the second half before Limerick reeled them back a bit. Then Walsh hit two goals in the fourth quarter to essentially finish the game as a contest.
Limerick rallied slightly to finish game well but the gap opened up by Walsh's strikes proved too big to bridge.
Notwithstanding that unexpected result in 2014, Limerick are again favourites for this weekend, except at a more inviting price.
Since then, they have steamrolled Wexford in an U21 final in 2015. As a mark of the quality of that side, seven players who featured that day will start Saturday's decider.
Indeed, the more precocious among them such as Cian Lynch and Peter Casey are already being heavily relied upon at senior level.
Can Limerick gain revenge against Kilkenny for the minor defeat of 2014 and claim a fifth All-Ireland success at the U21 grade this century? We'll see on Saturday.
