It's arguably the most crucial quartet in the modern rugby league team – the "spine" of fullback, halfback, five-eighth and hooker. These four players get their hands on the ball more than any other and are the players entrusted to control each set of six and create try-scoring opportunities for teammates. To be a successful NRL team, you need to have a strong spine.
According to the writers from NRL.com, these are the best of the best heading into the 2016 NRL season.
Spine: Josh Dugan, Benji Marshall, Gareth Widdop, Mitch Rein
One of the curiosities about St George Illawarra's 2015 season was why they couldn't seem to score points despite having such a star-studded spine. Mitch Rein is an underrated playmaker, Gareth Widdop and Benji Marshall are both hugely talented internationals and Josh Dugan is the current NSW fullback and one of the strongest ball-runners in rugby league. That the Dragons made the finals despite a struggling attacking game both shows how strong their defence was for much of the season and suggests there's room for improvement if Paul McGregor can get the best out of his creative players next season.
Spine: Roger Tuivasa-Sheck, Shaun Johnson, Tuimoala Lolohea/Thomas Leuluai, Issac Luke
If the Warriors' disappointing 2015 season suggested they relied almost exclusively on superstar halfback Shaun Johnson, that won't be the case in 2016. The NRL's lone New Zealand side has a choice of two strong utilities (and Kiwi internationals) for the five-eighth role – fit-again veteran Thomas Leuluai and super-talented young gun Tui Lolohea – but the real story is the arrival of massive signings Roger Tuivasa-Sheck from the Roosters and Issac Luke from the Rabbitohs. The Warriors now essentially have the spine of the world's No.1-ranked international team, and if things click it could make them a genuine premiership contender.
Spine: Billy Slater, Cooper Cronk, Blake Green, Cameron Smith
While the Warriors have a new-look combination, the Storm's 'Big Three' have been playing together for so long that they know each other's game back-to-front. Cameron Smith, Cooper Cronk and Billy Slater are not only first-choice Kangaroos but also possess a near telepathic understanding when it comes to performing Craig Bellamy's set plays, and Blake Green fitted into the side like a glove in his first campaign in Storm colours. It's never wise to write Melbourne off whenever these guys are still at the club.
Spine: Darius Boyd, Ben Hunt, Anthony Milford, Andrew McCullough
There was certainly excitement about the Broncos heading into the 2015 season, but few observers really expected them to be as successful as they were. Would Darius Boyd (and coach Wayne Bennett) get back to their best after some shaky years at Newcastle? Would Ben Hunt back up his breakout 2014 season? Could Anthony Milford excel at the Broncos at five-eighth? A resounding "yes" turned out to be the answer to all those questions, and with the underrated workaholic Andrew McCullough completing the quartet the Broncos are now widely tipped to play their way into another grand final in 2016.
Spine: Lachlan Coote, Johnathan Thurston, Michael Morgan, Jake Granville
Getting the right combination of players around champion playmaker Johnathan Thurston had always been the puzzle for the North Queensland Cowboys. Everyone knew Thurston was a player to build a team around, but giving him the support he needed had for years proved elusive for the Townsville club. But in 2015, it all finally clicked. Lachlan Coote came back from injury and played better than ever in his first full season in Cowboys colours. Michael Morgan backed up his breakthrough season at fullback with an even better one at five-eighth, taking the pressure off Thurston and earning a Maroons jersey in the process. Jake Granville fulfilled years of promise and became arguably the most explosive No.9 in the game, becoming yet another point of attack for North Queensland. With that support, Thurston produced his greatest NRL season, winning a fourth Dally M Medal and then leading his club to their first premiership.