Cape Town - All Blacks coach Steve Hansen is puzzled that they are set to lose their No 1 spot in the World Rugby rankings.
Wales will leapfrog New Zealand into first spot when the rankings are confirmed later on Monday.
The Welsh beat England 13-6 in Cardiff on Saturday and it was enough to leapfrog New Zealand, who thrashed Australia 36-0 in Auckland on Saturday to retain the Bledisloe Cup.
"How do you work that out?" was quoted as saying by the Stuff.co.nz website on Sunday. "We won the (Bledisloe) Cup last night and lost the rankings. Ask yourself how that works.
"I've never understood their system. You win a game and you lose the top ranking?
"When you sit back, it's something that's going to happen anyway - the top-ranked sides are playing each other in the northern hemisphere, and you get more points if you beat top sides.
"We just need to get ourselves in the right frame of mind to go to the World Cup and win that. I'm not too worried about rankings."
The All Blacks have held the top spot since November of 2009 - all of that run under Hansen's tutelage as head coach.
Wales have won 15 of their last 16 Tests, but have not faced the All Blacks during this period.