Sydney Roosters great Russell Fairfax believes the premiers' heavyweight showdown with Canterbury on Friday night will provide a telling insight into the tricolours' prospects of securing back-to-back NRL titles in 2014.
Brisbane (1992-93), Parramatta (1981-83), Canterbury (1984-85) and Canberra (1989-90) are the only sides to successfully defend a premiership since Fairfax's legendary 1974-75 outfit.
Super coach Jack Gibson masterminded both the Roosters' 1970s double and the Eels' 1980s treble and Fairfax believes it will take another special touch from Trent Robinson's class of 2015 to pull off the rare feat.
"It's incredibly difficult to go back-to-back nowadays because of the way technology moves forward on a daily basis," Fairfax told AAP on Thursday.
"Back in my day, there wasn't much change season to season.
"But here in the modern game, the fully professional game, if you're not improving, everyone else is and you can't expect to keep pace.
"So going back-to-back is probably one of the toughest hills to climb in rugby league."
Whereas Fairfax rated teams in his era a 50-50 hope of defending their titles, he's slashed the odds these days to about 20 per cent chance.
The exciting fullback of yesteryear said one advantage the modern-day Roosters have is they at least know what it takes.
"In my day, they weren't quite aware of what you had to do to go back-to-back," Fairfax said.
"They thought they'd just come along and turn up. Now they know that every player, not just one or two, as well as the coach, their tactics ... everything needs to improve by at least five to 10 per cent.
"Otherwise they're no chance."
Placing the premiers alongside Manly, Melbourne, South Sydney and North Queensland as joint title favourites, Fairfax believes Robinson's Roosters can complete the double - but only if they keep their galaxy of stars on the paddock.
"They need to have their full complement on the field," he said after offering a few words of wisdom to Roosters captain - and fellow fullback - Anthony Minichiello ahead of this weekend's Heritage Round.
"There's a number of players they can't afford to lose, let's be honest.
"Minichiello, you can replace him with a player at the back but he's the guy that holds them all together. He's the glue there."
Strike forwards Sonny Bill Williams and Jared Waerea-Hargreaves and NSW State of Origin halves James Maloney and Mitchell Pearce are also irreplaceable, according to Fairfax.
Minichiello agreed the Bulldogs at Allianz Stadium on Friday would be a stern test of the Roosters' title credentials and challenged his pack to outmuscle Canterbury's vaunted forwards.
While Waerea-Hargreaves will miss the match through suspension, Williams is returning from a three-game ban and his captain knows what he wants from the Kiwi international.
"Hopefully a man of the match performance. He's ready to play," Minichiello said.
"He's been jumping out of his skin the last two weeks. He's only played one game, so he's fresh.
"We're looking for him to have a strong game, that's for sure."