The Sydney Roosters ended the 2020 season as the NRL's oldest squad while last-placed Brisbane were the youngest.
The Tricolours, who fell short of a premiership three-peat when they were knocked out in the second week of the finals by Canberra, had an average age of 27.2 at the conclusion of the 2020 campaign.
The likes of Sonny Bill Williams (35), twins Brett and Josh Morris (34), Mitch Aubusson (33), Jared Waerea-Hargreaves (31) and Jake Friend (30) boosted the team's average age. They had five players under 23.
The three "oldest" sides – the Roosters, Parramatta (26.5) and premiers Melbourne (26.4) – all finished in the top four.
Minor premiers Penrith were the outlier of the elite, winning 17 straight despite being the second-youngest squad (24.8) in the competition. They had 10 players under 23 including Nathan Cleary, Stephen Crichton and Brian To'o.
Although youthful exuberance worked wonders for the Panthers, perhaps the Broncos needed a few more hardened players.
The wooden spooners ranked as the youngest team with an average age of 24.6 and 14 squad members under 23.
Canberra, who used a season-high eight debutants, had the next most under-23 players with 13, followed by the Cowboys (11).
Wests Tigers, St George Illawarra and Newcastle each had nine.
Aside from Penrith, the Raiders (25.5) and Rabbitohs (25.3) were the only finalists not to be in the top half of teams for average age.