Sir Alastair Cook has backed Chris Silverwood to bring the same clarity to England's Test cricket that he offered to Essex during his agenda-setting spell as head coach, and believes that the team's renewed focus on the longer form of the game will help bring out the best in his own successor as Test captain, Joe Root.

Speaking to ESPNcricinfo on the eve of the New Zealand Test series, Cook acknowledged that England's once-in-a-generation opportunity to win a World Cup on home soil this summer had led to an understandable prioritisation of their white-ball fortunes. But given the challenge of winning back the Ashes in Australia in two years' time, he sees no reason why the red-ball squad shouldn't be able to reach similar heights in the coming months.

"New Zealand is a good place for Chris Silverwood and Joe Root to start a new cycle," Cook said. "It's only a two-match series, which is a bit of a shame, as their recent history has brought some cracking matches. You feel a long way away from everywhere, it doesn't have the hype of an Australia or India series, but they are a brilliant side, and it's a great but tough place to play cricket."

Though it sits outside the Future Tours Programme, and will therefore not count towards the World Test Championship, England have recognised the New Zealand series as a vital staging post as they begin to give the old format a bit of TLC - having rather muddled through this year's Ashes, drawing 2-2 thanks to moments of inspiration from Ben Stokes in particular, rather than any coherent plan for Test success.

And Cook, who stood down as captain at the end of a 4-0 defeat in India in December 2016, midway through Trevor Bayliss's four-year tenure, is sure that the arrival of Silverwood as head coach will lead to a marked improvement in Test cricket - much as he oversaw Essex's rise from the second division in 2016 to a first Championship title in 25 years the following summer.

"Clarity, that is one thing he'll bring," Cook said. "He's very clear on what he wants and it's very simple what he wants. The players will know, they'll be very well prepared, they'll know exactly what he demands of them, and he'll be a real helping hand for Joe Root, taking a lot of pressure off Root in terms of off-field stuff."

Root's role across all formats has come under particular scrutiny in recent months. While there is no question about his enduring quality as a Test cricketer, his returns have slipped from the heights in recent years, along with his average, which - in spite of four fifties in five Tests against Australia - was 47.91 by the end of this summer's Ashes, the lowest it has been for five years.

Furthermore, Root's average as captain has slipped to 40.81 in 33 matches - leading many commentators to question whether the burden of leadership is cramping his obvious style as a batsman. Cook, however, believes that a change of sidekick could be the key to unlocking his potential.

"Trevor was a very hands-off coach, and he had a lot of success," Cook said. "But there are different ways of skinning cats, and you can see that Joe needs that support around him. That's quite obvious, and Silverwood and his team will give a bit more than Trev did.

"I'm not saying that's right or wrong, but I think that's what will happen. And I think we'll see the next stage of Joe Root's England captaincy career. Looking back on my [time as captain], I think I took two and a half years to feel totally comfortable in the role, in terms of what you know, what you want from the side, and how you go about all the extra demands. Joe Root is at that kind of stage, I think he'll bat at No. 4 again, and I'm expecting another spike from him."

Cook had sympathy, too, for the extent to which Root - a key member of the World Cup-winning squad - was forced to compromise his own team's ambitions to support those of the white-ball captain, Eoin Morgan.

"I don't think Test cricket was [marginalised] when Trevor first came in for the 2015 Ashes," said Cook. "But then, as the World Cup loomed, and the instant transformation of the 50-over team after 2015 brought momentum, I can see that [was true] for the latter period, those last two years.

"But that was mainly for the players, they had that goal of being world champions, which is something no England team had done before, and at home too, so the opportunity was massive and you can see how the focus migrated that way.

"But now the challenge will be doing it in both, and there's no reason why England can't be successful, looking at the facilities we've got and the players we've got."

If England are to find any sort of consistency in Test cricket, however, then the first thing they need to address is the flimsiness of their top three. Though Cook's own returns at the top of the order tailed off in his final year of Test cricket (with the notable exception of his glorious farewell at The Oval in 2018), his absence was felt throughout a torrid summer in 2019, in which Rory Burns' diligent crease occupation was the closest that any opener came to matching the sort of resolve that Cook displayed during his 161-match, 12,472-run career.

"It's been clear over the last six months that when England have played their best cricket, the platform has been laid at the top of the order," Cook said. "And it's not been runs scored but balls faced as well. As an opener you want to score runs, no doubt, but as Goochie says, you set up games, you have the opportunity at 0 for 0 when you want out to bat, to score 150 and set up a game of cricket.

"Trevor was a very hands-off coach, and he had a lot of success. But there are different ways of skinning cats, and you can see that Joe needs that support around him"

"Rory Burns faced a hell of a lot of balls," he added. "After one bad game against Ireland [6 and 6], a certain Sky pundit [Nasser Hussain] said he'd pick 'Opener A and Opener B' for the Ashes. So he did really well in tough conditions to come back and score a hundred in the very next game, especially compared to the Australian openers."

Burns' 'Opener B' in New Zealand may well be another player who has forced his way into the reckoning through his sheer weight of runs in county cricket. And while Cook anticipates a steep learning curve should Dom Sibley make his debut in next week's first Test, he believes he's already shown promising resilience in his short but eventful county career.

"He's done everything that's been asked of him - an amazing start with a double-hundred at Surrey against Yorkshire as a 17-year-old, then a bit of a downward curve, then in and out of the side before a move to Warwickshire. He's had a bit of a journey, and he'll have that same journey in international cricket.

"You're never totally sure how he will play amid all that scrutiny - he has a slightly different technique to what is so-called 'classical', but he will do what he will do, which is face a lot of balls and hopefully leave well, and if he gets off to a good start, hopefully we'll see a guy who is what Goochie calls a 'run-maker'. He's not going to blow sides away scoring quickly, but he will take a lot of shifting, and for this England side, that's exactly what they need."

The message, Cook believes, will be that England's top three will have licence to bat all day if needs be, because that will give the strokeplayers in the middle order - the likes of Stokes, Jos Buttler and, if he earns a recall, Jonny Bairstow - all the more opportunity to turn a match in a session with their natural free-flowing games.

"I wouldn't say there were mixed messages from Rooty and Trev to play positively, but there was confusion around how England want to play their Test match cricket," said Cook. "There has to be a platform laid, and I think we'll start seeing that under Silverwood.

"The top three will be very specific in their roles. Your job is to score a hundred, and if it takes you all day, that's your job - it's not how quickly you score. If you're batting at lunch, you are putting guys into their second and third spells, and if England are very clear on that, the message will filter down in county cricket. If you want to bat in the top three for England, you've got to be able to bat a long period of time. And if you can't, you won't."

Sir Alastair Cook was speaking at an event to mark 25 years of the National Lottery, which has raised £5.7 billion for grassroots sport. #BecauseYouPlay