The British and Irish Lions tour of New Zealand reaches its climax Saturday in the winner-takes-all series decider at Eden Park in Auckland.

After the All Blacks won the first Test, and the Lions beat them in the second, the outcome of the series has come down to the third and final Test.

The Lions arrived in New Zealand as underdogs, given their record of having won only seven of 40 Tests against the All Blacks since they first toured in 1888, and only once, in 1971, have they won a series.

But, in coach Warren Gatland's words, this Saturday at Eden Park is "their chance to make Lions history."

They sense they can pull off an historic second series win despite the final showdown at Eden Park, the New Zealand fortress where the All Blacks have not lost to any side in 39 Tests dating back to 1994.

A clinical All Blacks put away the Lions 30-15 in the first Test but their hopes of going 2-0 up the following week were crushed when a late Owen Farrell gave the Lions a 24-21 victory to level the series.

As tension mounted in the lead up to the decider, Gatland kept his winning combination, giving them multiple attacking options with Conor Murray, Johnny Sexton and Owen Farrell to target All Blacks rookies Jordie Barrett and Ngani Laumape.

Injuries and the suspension of Sonny Bill Williams forced the All Blacks to make three changes with Julian Savea also joining the starting line up with Barrett and Laumape.

Hansen is gambling on the exuberance of the trio at getting a first start in the series to ignite the expansive running game with deft off loads that the Lions have so far successfully shut down.

The All Blacks compensated in the first Test by out-manoeuvring the Lions with a close-quarter, pick-and-go game.

But they were beaten in the crucial forward battle in the second Test when they played most of the game without flanker Jerome Kaino who was substituted for an extra back following Sonny Bill Williams' red card.

An extra weapon in the All Blacks armoury is the long-range kicking talent of the younger Barrett should the Lions again concede multiple penalties as they did in the second Test.

Solving disciplinary issues has been central to the tourists build up this week particularly at the breakdown where the battles at the collision to secure the ball are likely to determine the result.

It is an area that will put French referee Romain Poite under the microscope.

Gatland's message to the whistleblower was to be consistent with his rulings and not be surprised if he finds the All Blacks under pressure.

"We’ve got the confidence and self-belief to win this Saturday and win the series," Gatland said.

"So all we ask of (the match officials) is to be open-minded, not to be surprised by us being in front and good enough to win."

All Black captain Kieran Read, who will be playing his milestone 100th Test, said the New Zealanders had prepared as best they could.

"The work's been done, which is great, now it's just about turning up and going out there and playing... we know the task that's ahead of us."