Ashley Giles says appointing Chris Silverwood as England head coach is his "biggest decision yet" and that he had "sleepless nights" before he made the call.
Silverwood was picked by Giles, England's managing director of men's cricket, as the man to succeed Trevor Bayliss after the Australian's four-year tenure came to an end.
Gary Kirsten, who has led India and his native South Africa to the top of the Test rankings, was seen as a strong candidate but Giles opted for Silverwood, who had been England's bowling coach since January 2018.
"It's the biggest decision yet," he said of the appointment of Silverwood, who coached Essex to the County Championship title in 2017, just one year after getting the side promoted.
"We had some very good candidates, all with different strengths and different plans. It took me a couple of long days, with sleepless nights but that's how it should be: it's a big job.
"I was delighted to make that phone call. When you can ring someone who really wants the job, who's worked really hard towards it, it's one of the better calls you make.
"Being able to flex your style across different environments is important. I do think this bloke [Silverwood] can do that."
Giles hopes Silverwood's previous success in red-ball cricket can help boost England's Test team, who currently sit fourth in the rankings, and, in particular, captain Joe Root.
"We want someone who is going to give Joe more support, put more structure in place around him and together form that DNA of what a Test team looks like, which I don't think we've quite got to yet," added Giles.
"That structure and support needs to go and allow Joe to average 50 with the bat, score hundreds and win Test matches.
"When it comes down to nuts and bolts that's the most important thing because it takes the pressure off everyone."
Silverwood is set to oversee a team of three assistants - Graham Thorpe and Paul Collingwood poised to be among them - who could step up and lead if the 44-year-old is taking a break.
Giles also says Silverwood will have a big say on the identity of the man who replaces him as bowling coach.
"If he's away from T20 cricket Colly would be the perfect man, if it's Test cricket there's an opportunity for Thorpey to lead," added Giles.
"There's a vacancy with the bowling. You need outside views as well sometimes, whether it's someone from a different country, a different age group or someone with a few more grey hairs then fine.
"It's an opportunity for Chris to have a bit of a free hit for who he wants in that role."
Giles also revealed he has spoken to both Ben and Clare Stokes after pictures emerged from last week's PCA awards in London showing the all-rounder's hand against his wife's face.
"We can all say domestic violence is a really serious issue and we're not making light of that at all but in this case it's a very happy couple having some fun - a picture telling a thousand words but just the wrong ones.
"I think it's just a worry in some sense as to how his profile can be used against him and how susceptible they are as a family to this. The bigger your profile the more difficult it can become.
"Part of my job is to protect them from that. We're certainly there for them. Player welfare and support is a big thing for us going forwards."
Watch England's tour of New Zealand live on Sky Sports Cricket next month.