Sky Super Rugby Transtasman: Two key reasons for New Zealand dominance over Australia, Blues coach Leon MacDonald

Through two rounds of Super Rugby Transtasman, New Zealand teams have won all 10 matches, and Blues coach Leon MacDonald has highlighted two key reasons as to why that might be the case.

Speaking after his side's 48-21 win over the Waratahs in Auckland on Saturday night, MacDonald suggested the Australian sides were a step behind the Kiwis when it came to execution and depth.

"They're willing. I think some errors creep in that you wouldn't get against New Zealand teams at critical times," MacDonald said. "They let you off the hook sometimes when they have you under pressure, but they're tenacious. I thought the Waratahs were really tenacious; they hung in there right until the very end.

"If you looked across the teams, I think an asset we have got at the moment is depth in our squads.

"We're rolling some good players off benches, trying to accelerate that go-forward. I think that happened in our game; our bench added some good punch and impact, and I think that's probably where we got a bit of an advantage."

Blues backs Bryce Heem and Jacob Ratumaitavuki-Kneepkens. Photo / Photosport

Against the Waratahs, the Blues only had 45 per cent of possession and conceded an equal number of penalties (12) but they were able to win nine turnovers to halt the Waratahs on attack.

But while the Waratahs might have felt they deserved more points, MacDonald was concerned by his side's defensive performance at times, as the Waratahs found ways to slice through the line.

"I thought we were off the pace with some of our defence early on," MacDonald said.

"We didn't apply a lot of pressure off the ball, which we wanted to do, and put their skill under some pressure. The challenge in a game like this where everyone is expecting you to win is how you really bring that edge. That was something we wanted to achieve and I don't think we really nailed that, which is disappointing."

While they have earned the maximum five points from both their opening fixtures, things only get tougher for the Blues, with the Brumbies, Reds and Force awaiting them in the run home.

The Brumbies and Force have tested their Kiwi opposition through the opening two rounds, and while the Reds have been soundly beaten twice, MacDonald said the Australian champions should not be underestimated.

"You'd probably say the three best teams to finish. We've got to keep improving and we have to be better.

"I can guarantee you some New Zealand teams are going to lose some games and we just have to make sure it's not us."