Storm winger Josh Addo-Carr.

Cooper Cronk versus the team he helped steer to last year's premiership and a top-four berth in 10 of the past 12 seasons.

That's the match-up many are predicting to fight out the NRL grand final after Melbourne quietly climbed to the top of the Telstra Premiership ladder during State of Origin and Cronk's Sydney Roosters recorded their third consecutive win with Sunday's 36-18 defeat of St George Illawarra.

However, the results of this year's topsy-turvy competition suggest 2018 could also be the first season a team from outside the top four has lifted the Provan-Summons Trophy since Canterbury won from sixth place in 1995.

While the top eight has been effectively decided for a month, the premiership race is wide open and every team who will be in the finals has proven at various stages this season that they are capable of winning.

The key is peaking at the right time and that is why many believe Cronk can help deliver the Roosters their second premiership in six seasons as the pre-season premiership favourites are only now starting to hit top form.

The win over the Dragons was the first time this season the Roosters have beaten another top-four team but the manner in which they did it looked ominous and the club's other major off-season signing James Tedesco is also having an impact.

The Roosters had previously won four consecutive matches from round 12 to 15 before losing 9-8 to Melbourne in Adelaide and have now won seven of their last eight games.

The Storm also appear to have got the balance of their team right after trying three halfbacks – Brodie Croft, Ryley Jacks and Jahrome Hughes – in the No.7 jersey made vacant by Cronk's off-season departure.

In the end, the answer to Craig Bellamy's playmaking dilemma was obvious – Cameron Smith and Billy Slater are now getting their hands on the ball in the first receiver's role, while Hughes is playing like a second fullback.

With Smith standing down from representative football, Melbourne were unbeaten during the Origin period for the first time in the club's 20-year history and are on an eight-game winning streak.

Each of the teams in the top eight have enjoyed similar unbeaten runs this season, with second-placed South Sydney winning nine consecutive matches before their round 19 loss to Wests Tigers.

St George Illawarra are the only team to have been in the top four for the entire season after winning their opening six games and eight of the first nine rounds, while they also enjoyed a three-match winning streak from round 14 to 16.

Cronulla, who are currently sixth, also won six consecutive matches from round seven, and three in a row between round 16 and 18 – a feat Penrith have achieved twice this season.

The Panthers, who are fifth, enjoyed a three-game winning streak from rounds four to six and won five of their first six games, while they won four consecutive matches between round 10 to 14 in the lead-up to Origin.

The seventh-placed Broncos and eighth-placed Warriors have both managed five-game winning streaks – the latter doing so in the opening five matches of the season, while Brisbane's run was from round eight to 12.

The Broncos also managed to triumph in eight of nine games as they won another three matches on the trot between round 14 and 16.

While the best form of the Dragons, Panthers, Sharks, Broncos and Warriors may appear to have been earlier in the season, there is still time for them to regain momentum and make a run at the title.

Besides the above mentioned winning runs, Wests Tigers is the only other team to have managed better than back-to-back victories this season when they won three successive matches from round four to six.

If the Storm were to maintain their current winning streak until the grand final, they would need to win 16 consecutive games – something that has never been done.

The Roosters would also need to win an unprecedented 12 matches without defeat if they weren't to falter again on their way to the premiership title.

The record is jointly held by the 1972 Manly side and the 1955 South Sydney team, who each won 11 straight games including their grand final triumph.

Melbourne last year won 10 games in a row to claim their second premiership since the salary cap scandal of 2010.

The Storm also won eight consecutive matches including the grand final in their previous premiership triumph in 2012.