Speaking on The Rugby Rivals podcast with Sir John Kirwan and Ric Salizzo, Matfield said the All Blacks win away from home and have two home Tests against South Africa.
"Whoever is going to win this Rugby Championship has to get past New Zealand."
Matfield said he couldn't understand why Beauden Barrett, a two-time World Rugby player of the year, was ever doubted in the role of first five-eighths.
"He's an unbelievable 10 and a much better 10 than a 15 [fullback]. It's always better to play against him if he's not a 10.
"Maybe he's not the goal-kicker that Dan Carter was, but now he's kicking really well.
"I think the balance he brings to a game; when he kicks, when he plays, when he takes the line on, the speed that he's got. He's unbelievable."
Matfield also noted that the All Blacks scored three maul tries in their Championship opener against Argentina at the weekend. In comparison, South Africa did not score one maul try in their loss to Australia.
"New Zealand go out and they have got their balance right; when to play, when to kick the ball in behind them. Not defensive kicking, attacking kicking, putting it behind, forcing them to turn around, and then their forward pack using their energy to score tries.
"When you get into that 22, go at them, use your maul, go around the corner and be effective."
Kirwan said lock Fabian Holland has been a find for the All Blacks.
"His work rate, his running around the field, he's making his tackles. We've got a real gem there that can build into a world-class lock."
Matfield said there is a lot of talk about Holland's big body, but he was impressed with Tupou Vaa'i playing lock last year.
"I thought he was outstanding."
He also wondered what would happen when Wallace Sititi comes back into the side.
"He must get in there somewhere. I don't know if you will play him at eight, or if he will go to the blindside and Savea go to the openside. It's a nice problem to have. At this stage, it's working.
"You said you guys want a big body in there who can enforce and have an impact. At the moment, it's working.
"I'm looking forward to that Eden Park Test match."
The traditional rivals are at different stages of their build-up to the 2027 Rugby World Cup. All Blacks coach Scott Robertson is looking to get his preferred side playing together as often as possible to develop combinations, while also building back-up support beneath them.
However, that was not something two-time Rugby World Cup winner Rassie Erasmus believed in.
"You never know who he's going to pick, it's almost like the French, you never know who they're going to pick. Yes, there was this one failure now, but so far he's been very successful.
"This is the best Springbok era we've had. We've never been so successful. It's very difficult after one Test match to say that whatever they are doing is wrong."
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