'England v New Zealand series key to Alastair Cook's Ashes hopes'

Alastair Cook has lost only two of his eight Test series since being appointed permanent England captain

For the last 12 months, the only constant in the leadership of the England team has been Alastair Cook.

There is a new chairman of the England and Wales Cricket Board, a new chief executive, a newly created role of cricket director and even a new head of media.

Closer to the team, Peter Moores has come and gone as coach, with the position still vacant.

Yet some things remain the same.

As the Test summer begins against New Zealand at Lord's on Thursday, England are coming off the back of another episode in the never-ending Kevin Pietersen saga, one remarkably similar to February 2014 when Pietersen was told his England career was over.

Although we knew then that Cook had a hand in the decision to discard Pietersen in that he was present at the infamous meeting with Paul Downton, recent reports suggest it is clearer than ever that Cook simply does not want the Surrey batsman in his team.

That in itself does little to change the perception of Cook the skipper. Indeed, most are so entrenched in their views about Pietersen that virtually nothing can be done to alter them.

If you believe Pietersen should or should not be in the England team, by now nothing will change your mind. The same goes for your view on whether Cook is a good captain or not.

The battle lines have been drawn and the two sides constantly shoot over the top.

Still, that does nothing to alleviate the pressure on Cook at the beginning of what could be a defining summer in his time as England captain.

A poor Ashes series will probably lead to his removal, especially now Joe Root has been appointed vice-captain, while the preceding series against New Zealand will determine the mood of those opening battles against Australia.

If England defeat New Zealand, they should be given credit for beating a more than decent side two places above them in the International Cricket Council Test rankings.

Should England lose, they should expect the disquiet among a vociferous section of their support base to gain volume. It would be the worst way in which to enter the Ashes.

Howdy, partner

Yorkshire opener Adam Lyth averages 43.20 in 103 first-class matches

At whatever point Cook walks out to open the batting in the first Test at Lord's, he will do so with a new opening partner, his sixth since the retirement of Andrew Strauss in 2012.

The last of those was Jonathan Trott in an experiment that was always more likely to end in failure than success. You simply cannot gamble with the opening pair - it's too important a job.

The next man to get a chance will be Adam Lyth and England will be hoping that, for the sake of stability, he takes his chance. Importantly, he has earned his chance, which is what international call-ups are about.

I spoke to Lyth on the tour of the West Indies this year and he was bursting with enthusiasm and pride, which is great to see from an England debutant.

He plays more of an attacking game than Cook, which should result in a nice blend. Openers don't have to smash it about, but it is advantageous for at least one of them to be able to move the score along right away.

Some are saying it is a bad time for him to make his debut, with only two Tests against a good New Zealand attack and then the Ashes, but that is rubbish.

You do not choose your time to play international cricket - you simply must take the opportunity when it comes. All he has to do is bat well.

Which seamer to pick?

Mark Wood made his England ODI debut against Ireland in May

That England did not beat West Indies was down to their conservative selection policy and, more specifically, failing to field an attack capable of taking 20 wickets on benign pitches.

In having all-rounders Moeen Ali, Ben Stokes and Chris Jordan at their disposal, England have the strength of flexibility. However, they are in danger of a strength becoming a weakness.

If Moeen is the first-choice spinner, then fine, but Stokes and Jordan - both a little wet behind the ears with the ball - should probably be competing for the same place.

In the Caribbean, they both played all three Tests, took only nine wickets between them and kept the leg-spin of Adil Rashid and extra pace of Liam Plunkett out of the side.

With neither Rashid nor Plunkett in the squad to face New Zealand, I would like to see uncapped Durham seamer Mark Wood given a debut in conditions that are likely to be helpful for bowling New Zealand out twice.

I have not seen much of him, but I know former England captain Michael Vaughan is an admirer.

England must find some wicket-taking alternatives because they are only one James Anderson injury away from a huge problem. This is an ideal opportunity.

Freedom for Farbrace

Assistant coach Paul Farbrace, asked to take charge for the two Tests against New Zealand, finds himself in a useful position.

There is low expectation of him and, although Yorkshire coach Jason Gillespie appears to be the favourite, if Farbrace guides England to victory you can imagine a scenario where he becomes a candidate for the job.

Farbrace has had success leading an international team with Sri Lanka, albeit in limited-overs cricket.

He is a personable man and an encouraging coach, one who will want the players to relax and enjoy themselves. He has worked with the likes of Kumar Sangakkara, Mahela Jayawardene and Tillakaratne Dilshan, talented cricketers whom he will not have suppressed.

Farbrace knows how to deal with international sportsmen. He will encourage the players to perform at their best, without heaping the pressure of expectation.

New Zealand, the team England want to be?

New Zealand have been beaten only once in their past eight series, by England in 2013

New Zealand are a strong side, led by the ultra-aggressive Brendon McCullum and with a number of incredibly talented players in their ranks.

If there is a chink in the armour, is that a number of them have only arrived from the Indian Premier League this week, with the financial state of the game back home meaning these guys have to be allowed the longest possible IPL opportunity.

However, I don't see that affecting them too much, especially the very dangerous new-ball pair of Tim Southee and Trent Boult, who will simply switch from swinging white ball to swinging red ball and probably enjoy respite from batsmen trying to whack them out of the park.

The batting is packed with exciting stroke players. Not only McCullum, but the vastly improved Kane Williamson, experienced Ross Taylor and Martin Guptill, who had such a successful World Cup as the Kiwis reached the final.

On top of their ability, New Zealand are immensely popular because of the way they play the game. It is positive and uncompromising, but within the right sprit and free from histrionics.

As England embark on yet another new start, they take on a team that they perhaps would like to be.

Jonathan Agnew was speaking to BBC Sport's Stephan Shemilt.