The players filling the roles of hooker, halfback, five-eighth and fullback form the backbone of any rugby league team, and hence the four positions have become known collectively as the team's spine. It is plain to see that a team's hopes of NRL premiership glory are slim if it doesn't have quality players in these vital positions.
The 2018 NRL season will open with more spines having been adjusted than in the local chiropractor's office. With the players settling into their new colours, ESPN has taken a new scientific approach to determining which team came out on top after the great halves shuffle We have gathered five key statistics from the 2017 season, averaged them out per game played and totalled those figures to give a definitive number.
Melbourne Storm, last year's premiers come out on top, even after losing Cooper Cronk to Sydney Roosters. Statistically at least, the Storm lose very little with Brodie Croft slipping on the purple No. 7 jersey.
More surprising was the position taken up by last year's beaten grand finalists, North Queensland Cowboys. Any spine boasting Michael Morgan and Johnathan Thurston would seem to be worthy of a more lofty ranking, but Lachlan Coote and Jake Granville let the team down statistically -- particularly Coote's running metres.
The Panthers slip into second place after welcoming high-performing five-eighth James Maloney from the Sharks. Fullback Dylan Edwards gives them a boost as well with his ability to run the ball.
The Rabbitohs are surprisingly high on the list, but their fourth position owes a lot to the way Greg Inglis played in 2016. After a season on the sidelines, it will be interesting to see whether he will be back to his best.
Of course, a high-quality spine does not necessarily guarantee premiership success; New Zealand Warriors were solid proof of this last season, when they boasted one of the best spines ever assembled yet still finished the campaign just two wins above the wooden spoon.
P = points, T = tackles, TE = tackle efficiency, M = metres run, TA = try assists
(Statistics from the 2017 season unless noted, averaged per game played)