Smash on the door long enough and Steve Hansen will eventually answer.
Proof is the selection of young Chiefs lock Brodie Retallick in the All Blacks' starting XV, named yesterday to play England.
The 21-year-old is the major talking point of the three changes to the team that will run on to Twickenham on Sunday (NZ time).
Dan Carter returns at first five-eighth for Aaron Cruden, while hooker Keven Mealamu comes in for the suspended Andrew Hore.
The selections of both Carter (Achilles) and Mealamu (calf) were dependent on their coming through today's training unscathed, but Hansen has essentially named his best available side.
And it is no small feat that Retallick is in that team at the end of a remarkable first test season.
Since making his debut against Ireland just a couple of weeks after celebrating his 21st, he has taken part in 12 of the All Blacks' tests and made seven starts. Hansen has spoken all year about managing his workload and taking things easy as he rotated Retallick with another impressive rookie in Luke Romano.
But this week he has made his choice for the biggest test of the end-of-year tour.
"He's had a couple of games off the bench and has a big motor and goes all day long," Hansen said.
"We just think this game will suit him. It gives Luke a chance to have a break.
"Both of them are rookies and have had a big year so it's just an opportunity to subtly change it, but not too much."
Few will argue with Retallick's selection. It is difficult to remember an error this year, other than a few mistimed kickoff receptions, and his considerable bulk, 117kg, and height, 2.04m, provide upside against the big England pack.
"They are big men, one of the biggest packs we'll come up against," Hansen said. "They play a physical, combative game - there's no question mark over where they're going to come - one off runners, two runners around the corner - and they are going to come straight at you.
"Outside of the set-piece, which will be a major, we have to make sure we dominate that area, and then we have to come forward and dominate tackles.
"Our own ball carrying will have to be good, because if you win that collision you win the match, I think."
If there's a work-on for Retallick, carrying the ball may be it, and Romano's edge has been his ability to take the ball up from phase play.
But Retallick is undoubtedly a massive prospect, powerful in the scrums, effective for a tall man at the cleanout and mobile enough to play the expansive style the All Blacks and nippy halfback Aaron Smith clearly plan to impose upon England, if the weather allows.
In naming his last test 23 of the season Hansen has shown himself to be a coach who leaves nothing to chance.
It has been noticeable at training this week to see two extra players, Tom Taylor and Hika Elliot, called up.
The pair represent a savvy, but expensive, insurance policy for a coach who arguably had things covered already. Should Mealamu withdraw because of his injury, Elliot would come into the reserves behind Dane Coles, but Taylor will not be on the bench, regardless of Carter's fitness.
Under that scenario, Aaron Cruden would start at first five-eighth. Beauden Barrett would come into the reserves and Tamati Ellison would replace Otago utility Ben Smith in order to provide better cover at second five-eighth.
All Blacks: Israel Dagg, Cory Jane, Conrad Smith, Ma'a Nonu, Julian Savea, Dan Carter, Aaron Smith, Kieran Read, Richie McCaw (c), Liam Messam, Sam Whitelock, Brodie Retallick, Owen Franks, Keven Mealamu, Tony Woodcock. Reserves: Dane Coles, Wyatt Crockett, Luke Romano, Charlie Faumuina, Victor Vito, Piri Weepu, Aaron Cruden, Ben Smith.
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