The 28-year-old loose forward is widely considered to be one of the All Blacks' best and most important players, which was backed up by his performances in the black jersey this year.
He said the negotiation process took almost a year and he felt he got added value once he was named as All Blacks skipper during the season.
"This process kind of took a while and the length of it was probably the longest you negotiate a contract.
"I became real intrigued in contracts and what people get paid … how do they know their value, how do they judge it. I was real intrigued in that many years ago. For me, it was like I had been [through] enough in my career to understand what goes on – the kind of base of it. It was only a thought in my mind to do it, I was too scared, but then I just kind of had people affirm me.
"My thinking was more around challenging myself but also I wanted a seat at the table so when it came time to crunch and fight for myself, there's no better person to go battle for me as myself."
"I was negotiating a deal and then I got named skip and I still hadn't signed, so I was like 'Now that I'm skip, s***, my value's gone up'. That's just the risk and reward," Savea said.
"The longer you wait, you might get injured and then the deal's gone. Or you wait and things like that happen, being named skip, being a leader, playing well, and it just increases your value to be able to negotiate more. The timing of it, the risk and reward of holding your negotiating it, is pretty important.
Savea has played 59 tests for the All Blacks since his debut in 2016 and was a key figure this season, starting 10 of 15 tests and captaining the team four times during the Rugby Championship, becoming the All Blacks' 70th test captain. He made his Super Rugby debut for the Hurricanes in 2013 and has gone on to play 108 matches, captaining the side in 2021.
Savea said he's confident he'll remain at his top form for the entire four years but learned from his brother Julian who got released from his New Zealand Rugby contract after struggling to make the test squad.
"Jules, for example, signed a four-year deal. He was getting paid top dollar and then he didn't make the All Blacks in one of his still contracted years, they were still paying him top dollar. Eventually, Jules asked for an early release. They granted him an early release and then he was able to go overseas.
"If worst comes to worse and I'm playing poos and I don't make the All Blacks, I'll still be getting paid a good contract and NZR probably don't want to do that, so they'll probably grant me a release and then both parties are happy. That was my strategy around negotiating a four-year deal – but I back myself to stay here and leave a legacy."