By his own admission, McCaw was some way short of his best during the second test in Dunedin, perhaps still showing signs of an injury-enforced spell on the sidelines earlier this season. The flanker has been back on the field since last month but appeared off the pace as England helped themselves to a halftime lead at Forsyth Barr Stadium.
Encouragingly for player and team ahead of the third test at Waikato Stadium, McCaw bounced back to aid in the All Blacks' second-half revival, but he knows there remains ample room for improvement.
"It's all right," he said of his form. "I wouldn't say it's the top-of-the-drawer just yet. In the second half, it felt easy and that's the way it is when the game's going well - you're getting on and doing things. The first half, I made a couple of mistakes and that gets on top of you.
"But they're easily fixed, you've just got to make sure you go about your business. It's okay but it could always be better and that's what we're always aiming to do."
That micro aim will surprise few, considering the All Blacks are seeking to dominate world rugby unlike any side seen. Another important step on that road could arrive this weekend, when they can level the major nations record of 17 straight victories.
This is the second chance McCaw and his colleagues have had to tie the mark held jointly by the 1965-69 All Blacks and 1997-98 South Africa teams. The previous instance, two years ago in Brisbane, ended with a disappointing draw against the Wallabies, and McCaw hoped lessons had since been learned.
"We're not going to not talk about it - it's just one of those things where if we do the job right, it'll be a nice little thing to have."
So, too, would a mental boost ahead of the World Cup defence next year. With the rivalry against England growing by the game, Hamilton holds the penultimate chance to inflict some psychological damage before the tournament on English soil.
While McCaw was uncertain about the effect another defeat would have on the tourists, he was intent on discovering just that.
"I think the underlying feeling within the team is that we haven't put a performance together that we're really proud of."
McCaw v England
First test
Metres: 8, Carries: 6, Tackles: 12, Missed tackles: 3; Turnovers won: 2.
Second test
Metres: 9, Carries: 9, Tackles: 9, Missed tackles: 2; Turnovers won: 0.