Michael Vaughan
Ex-England captain on BBC Test Match Special

"Good shot from Lyth to get your first fifty in Tests. Even when he scored seven and 12 at Lord's, he looked like a player, he looked controlled, he looked like he had a game that would match up well to Test match cricket."

Henry strays down the leg side and the ball disappears past Ronchi for four byes. Lyth prods the ball towards short mid-wicket and initially sets off for a single before thinking better of it. A maiden over, and the crowd is getting a little restless, which may have something to do with the amount of alcohol consumed so far. We have another 49 overs scheduled to be bowled today.

Andrew Samson
BBC Test Match Special statistician

"This is England's first century opening stand in a home Test since Birmingham in 2011 when Cook and Strauss added 186 against India."

Cook went on to get 294 in that game.

Image source, AP

Now it's Cook just three runs shy of a Test fifty - though in his case, it would be his 41st (with 27 centuries also in the bank). It would also be his fifth score in excess of 50 in seven Test innings. But for now, he's on the defensive as Craig (5-4-2-0) spins down another maiden.

Michael Vaughan
Ex-England captain on BBC Test Match Special

"For the team issues, Adam Lyth scoring runs today is massive. He is playing so well and looking so calm, looking controlled. All the jigsaw puzzle pieces are looking more in place than they did a just a couple of weeks ago."

Cook breaks the run of maidens as he cuts Henry to the cover point boundary for four. A single draws him level with Adam Lyth on 47 - and that's the cue for the Yorkshire left-hander to work a four off his legs to bring up his maiden Test fifty in only his third international innings. It's also the century stand, so smiles all round for the England fans. Having been marooned on 47 for a while, he's shuttling along nicely now with another two through point.

Luke in Southend: As a proud(ish) Essex Man, it's good to know that my much maligned county will soon be synonymous with both slippery men who sell cars with questionable back histories and classy Test batsmen with unquestionable batting pedigrees.

Dan in Hertfordshire: What's better, Cook overtaking Gooch or Jimmy reaching the 400 club? And whose attributes would you prefer to have between the two men? I would have to say Jimmy for both, although I'd rather have Cook's personality.

Image source, Getty Images

Craig, bowling in his sunglasses, keeps Lyth tied down again, there's momentary excitement among the fielders when the Yorkshire opener sweeps and misses, but the ball was clearly disappearing well down the leg side. Maiden, the third in succession and the fourth in five overs.

England 93-0 (35 overs)

Batsmen: Lyth 47*, Cook 42*

Bowling figures: Boult 12-3-29-0, Southee 12-1-39-0, Henry 8-2-21-0, Craig 3-2-2-0.

New Zealand 350 all out (Ronchi 88, Latham 84, Broad 5-109)

England won toss

Full scorecard

Michael Vaughan
Ex-England captain on BBC Test Match Special

"The most amazing thing about Alastair Cook's record is that he's only 30 years of age."

Image source, AFP

Bryan Waddle adds: "There's a good five or six years left in his game."

McCullum is still carefully directing his fielders as a bye advances the score - apart from that last four from Cook, we've had a good couple of dozen dot balls in the last four overs. Another maiden - with the bye not counting against the bowler - and the players have earned some drinks.

Bryan Waddle
BBC Test Match Special

"This is a nice steady organised partnership. The batsmen are in control of proceedings. New Zealand are finding very little encouragement in good batting conditions."

Cook carefully plays out another maiden from Craig. With both batsmen approaching a half century, do the "nervous nineties" have a forties equivalent? Fearsome forties?

Dan Gaylor: For all his supposed captaincy flaws Cook's tenacity, bloody mindedness, and dedication is second to none... a true great opener and I think it's only in time after he's retired people, will truly appreciate how special this guy truly is!

Sean in Derby: My favourite Cook memory has to be five years ago. I was bed ridden with a nasty bout of tonsillitis. Cook was batting to save his Test career against Pakistan at the Oval. His 110 that day did more to clear the infection than any dose of TCP that my mother had prescribed!

Aussie Fawlty: Poms who live down under will never forget his 766 runs at 127.66 in the 2010-11 Ashes series. May history repeat itself in the next few months.

Image source, Getty Images

Cook moves into the forties, thrashing a Henry full toss for four past the bowler. Boult, now patrolling the boundary, is rapidly signing autographs between deliveries - but every time he turns back to the crowd, there are around 20 youngsters thrusting miniature bats in his direction for him to sign.

Stephan Shemilt
BBC Sport at Headingley

"One chap has come dressed as the Queen, complete with mask. Every time he gets up to get a pint/go to the loo/meet the Prime Minister, the Western Terrace belts out the national anthem. Rousing."

Image source, Getty Images

In fact, it's a double change as the bearded Mark Craig is on to bowl some off-spin from the Kirkstall Lane End, having sent down that solitary over before lunch. Lyth, perhaps sensing the approach of that maiden fifty, plays out a maiden.

If you're just joining us, you can read all about Alastair Cook the record breaker on the BBC Sport website.

Image source, PA

Image source, @ICC

Rookie error from the ICC, who have misspelt Alastair Cook's name in this congratulatory tweet., external

Geoffrey Boycott
Ex-England batsman on BBC Test Match Special

"I think New Zealand have bowled pretty well - Southee has improved from the first Test - but the pitch has flattened out and England are sitting pretty."

A change of bowling as Boult is replaced by third seamer Matt Henry - as we've observed before, New Zealand don't have the greatest of bowling options (four front-line bowlers, one part-time spinner, a couple of non-bowling batsmen and four wicketkeepers). A bouncer to Lyth is deemed an aerial wide, while a single takes him to 47.