A tactical and preparation overhaul helped New South Wales produce one of the finest performances in State of Origin history in Game I and as Kylie Hilder's side looks to wrap up the series they'll again turn to a masterstroke that originated right under Queensland's nose.

The Blues underwent an extended, seven-week training camp before their 22-12 win over the Maroons at Lang Park earlier this month which boosted the team's cohesion and ensured the rustiness which has occasionally plagued them in series openers was a thing of the past.

Along with Olivia Kernick's promotion from the bench to starting at lock, it helped tip the scales against the favoured Queenslanders.

Kernick missed out on player of the match honours but dominated proceedings in the middle of the field, running for a game high 171 metres and making 21 tackles without a miss.

Her passing out of first receiver was also a highlight — a well-timed Kernick pass helped create the first try of the night and she consistently helped the powerful New South Wales forwards isolate defenders.

Better known as an edge forward, Kernick's move to lock began during her stint with Tweed Heads in the Queensland Women's Premiership and has helped tip the scales of Origin towards the Blues ahead of Game II in Newcastle on Thursday.

"I was playing for Tweed with a couple of other NRLW girls and we didn't have a lock forward. I'd been wanting to move into the middle, just to get that extra fitness under my belt, and I really liked it," Kernick said.

"I missed a few weeks of camp but then I came down, played lock in three of the trials and I guess I did alright because Kylie (Hilder, Blues coach) put me there. I really enjoyed it, it's a new challenge and I love it.

"When I played edge at the Roosters I do it as a ball-playing backrower and I love that but in Origin it's more about running backrowers.

"Moving to lock, I got to keep passing — I played a lot of touch going up, so I'd like to think it's natural for me."

Kernick starred at lock for the Seagulls — she averaged 144 metres per game after making the switch and led the competition's player of the year voting when voting went behind closed doors.

She's is no certainty to start at the back of the scrum next week but the Blues look sure to embrace a more expansive style regardless — Roosters hooker Keeley Davis has again been named to start at lock with a similar view to using the ball as much as possible an in effort to wrap up the series.

That competition for spots was key to getting the best out of the side during their marathon camp with the fight for backrow minutes particularly competitive.

It got the best out of Kernick and second rower Yasmin Clydsdale, who claimed player of the match honours with a barnstorming display down the left edge.

"It was six to seven weeks and we'd do two sessions a week in Sydney. I live in Scone, so it was a lot of time in the car, but it was the best thing we could have done as a squad," Clydsdale said.