2017 NRL - Grant Trouville © NRL Photos

State of Origin is here and aside from being one of the most fiercely contested events in world sport, it is also a game of fine margins. 

Origin is a perfect storm of individual brilliance, team work, passion in the Blue or Maroon jersey and the X-factor. Some would attribute the Queensland Maroons' recent dominance, where they have won 10 of the last 11 State of Origin series, to this X-factor. 

But what exactly is that – is it the 'spine'? We dug into the numbers to find out. 

  • Teams with a settled combination of hooker, halfback, five-eighth and fullback – the spine – have a 42 per cent chance of winning in Origin.
  • Teams that have new or unsettled spine combinations have a 28 per cent chance of winning.

A closer examination of the statistics reveals that in the 108 State of Origin matches played since 1980:

  • NSW have fielded 74 different fullback, five-eighth, halfback, hooker combinations, losing 57 per cent of matches they played with an untried spine.
  • Queensland have used 51 different spine combinations and won 58 per cent of matches in which they had a new quartet.

The Maroons' unprecedented era of domination coincided with their preferred spine of Cameron Smith, Billy Slater, Johnathan Thurston and firstly Darren Lockyer, then Cooper Cronk, playing together almost continuously for eight series. From 2009 until Lockyer's retirement in 2011, the former Australian captain's combination with Smith, Slater and Thurston yielded Queensland six wins in eight matches, and the most successful spine in Origin history also played together in the first two games of the 2005 series. 

With Cronk taking Lockyer's place in the Queensland spine in 2012, the Maroons barely missed a beat – except in 2014 when the Melbourne halfback was injured in the opening game and missed the second match, both of which were won by NSW as the Blues ended an eight-year losing streak. 

In addition to Queensland not being able to field the spine which has won them five of the eight Origins they have played together, NSW kept the same fullback, five-eighth, halfback, hooker combination of Jarryd Hayne, Josh Reynolds, Trent Hodkinson and Robbie Farah for the entire series. The only other series since 2005 in which NSW has kept the same spine for all three matches was in 2012 when they came very close, winning Game 2 and losing Game 3 after a late field goal from Cronk.

With Reynolds and Hodkinson also being the Canterbury Bulldogs halves, the NSW spine in 2014 were able to quickly develop an understanding of each other's games that the Blues have lacked for most of the past 12 years as they churned through 19 different halfback/five-eighth pairings alone. Farah was in career best form and the NSW selectors finally decided to leave Hayne in his preferred fullback position. In comparison, Thurston has played just five matches since 2005 without either Lockyer or Cronk as his scrum base partner due to injury, with Karmichael Hunt and Scott Prince filling the role during the 2008 series and Daly Cherry-Evans deputising in 2014. Smith has also missed just one Origin since debuting in the third match of the 2003 series.

Given the importance of the spine, the 2017 State of Origin series presents fans with a major tipping conundrum. Both teams are trialling new combinations – NSW by choice and Queensland because of the injury that has ruled out Thurston. 

The Blues have an opportunity to exploit an unsettled Maroons spine which is missing not only JT for the first time since 2004, but also Slater (seven series wins) after he was overlooked for Darius Boyd at fullback. 

Will the NSW spine of James Tedesco, James Maloney, Mitchell Pearce and Nathan Peats settle quickly and put Queensland to the sword or will the Maroons adjust and take advantage of their two home games?

Whatever happens, Origin 2017 promises to deliver an enthralling contest between two very even teams. Is the spine the X-factor, or is it a piece of individual brilliance that will turn the series? Only one way to find out!

This article first appeared on NRL.com

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