Shane Jurgensen is the quiet but meaningful presence behind New Zealand's pace battery. He was 32 when he was first appointed as the team's bowling coach in 2008. He served for three years before taking on the same role with Bangladesh, and then returned in 2016, when the New Zealand pace attack was gathering steam. With his contract now extended to 2022, he is New Zealand's longest-serving coach. We spoke to Jurgensen about how he has helped shape arguably the best bowling attack in New Zealand history.
You have witnessed real change within the team over the last 13 years as the longest-serving coach in New Zealand cricket history.
It all comes down to the players, really. From around 2009, it started with Daniel Vettori wanting to constantly improve and push outside the comfort zone. The attitude to work hard and get uncomfortable are some of the small improvements over the last ten or 11 years.
The systems in place, not just around the team but also in selection, have been a strong asset for this side.
In terms of performances on the field, I think another big area is the foundation built around the success of the Test side for a number of years. With that success in the toughest format, you have the opportunity to create depth. An important factor has also been that a lot of the players really challenge each other to get better.
Given their quality, how much of your work involves offering technical help to Trent Boult, Tim Southee and Neil Wagner?
My role constantly changes around understanding their technique and what drives their success [technically]. It can be from the simple bowling action they have, what they do when they are performing well, and how it looks when they have challenging days. My role is to understand them individually as bowlers.
It also includes their physical preparation around how many overs they will bowl and how they prepare for not just a match or series but the whole home summer. There's a lot of planning that goes on behind the scenes, working with other members of the support staff and head coach Gary Stead.
For example, how does their bowling action look for certain deliveries? Tim [Southee] and Trent [Boult] are outstanding outswing bowlers, so we are ensuring they are executing that as well as they can, ensuring the little technical things they do before delivering the ball and getting it right.
How hesitant or not are you to introduce changes in their bowling action when, for example, you spot something that needs attention?
We play a lot of international cricket at a very high intensity. The guys probably play ten months of the year for New Zealand and in the IPL. So slight little errors might creep into their bowling. Or it might be that they are coming back from a bit of a break. So little things, like a bowling action might be starting too early in relation to their run-up. A front arm isn't operating as powerfully as they normally would. Or they are not following-through in a certain manner to deliver an outswinger, a yorker or a slower ball.
A major part of my role is to identity those things. More importantly, work with the player so they trust I have their best interest at heart to ensure they are executing [their skills].
"We pride ourselves in being a threat to the opposition regardless of the situation of the game. We are trying to be consistent all the time, challenging ourselves and pushing our limits as a bowling unit"
How does Trent Boult manage to switch between formats so often?
With his success in the three formats, he has developed a lot of self-belief in his skills. Trent can basically [switch] very quickly through keeping things quite specific and simple. He has been able to stay in the game for a long period because he is extremely fit. He has a huge focus on his fitness. It has enabled him to bowl long spells in Tests and then adapt to ODI and T20 cricket. He is always a threat. His wicket-taking ability has been a major reason why he has consistently played and done very well in the three formats.
What's your approach with Neil Wagner, who can sustain high-intensity bowling all day long in Tests?
Wags has certainly been very successful over a long period at challenging the batter's footwork. He works closely with the senior team-mates, like Kane [Williamson]. When he starts to really challenge the batter, it is about the timing of it and making subtle adjustments in the field.
To his credit, a lot of wickets in the last 12 months have been through his desire to constantly improve and evolve as a bowler. Along with his attack of banging it in, particularly this summer, he has taken a lot of wickets with his outswingers to left-handers and inswingers to right-handers. That's down to Neil constantly wanting to improve.
I try to manage him with his overs because he loves to bowl. I try to ensure that his bowling action is solid through all those overs. Make sure he is nice and strong, which is a key asset to his overall balance when he delivers the ball.
Tim Southee, a bowler you encountered as a youngster in your first stint as coach, is now the senior statesman of the side. How has he managed his role in the bowling attack?
He has certainly evolved as a cricketer and person over a long period to complement his bowling. Recently you have seen him fill the role as T20I captain. He is a very good leader in the bowling group with his experience and success over a long period. He provides some really good messages to the side.
A lot of Tim's success comes down to his resilience and overcoming adversities. He is extremely fit. He is able to adapt and find ways to take wickets. To complement his very good outswinger, now he is well adapted to T20 cricket with various slower balls. He always had a very good yorker. He is extremely accurate at challenging the batsman. He is a very skilful bowler.
You have this habit of walking around the ground and speaking to the bowlers from the boundary line. What sort of things are you saying?
We are obviously providing water, but another part is to provide a sounding board for certain players if they are a little frustrated at things when it may not have gone to plan. I might ask them a question about whether they have considered something in particular in their attack - a type of delivery or a field placing.
Honestly, it can simply be supporting the player and being someone who listens. A lot of the ideas come from the player, so they talk it through. All of a sudden, they think of something. Or it might be to ensure that they have confidence in what they are trying to achieve. I am just there to provide that support.
"The 2019 World Cup semi-final against India was a unique situation played over two days. I was really proud of the way the bowlers challenged India in defending a 240-odd total"
Does having Boult, Southee, Kyle Jamieson and Wagner, and the string of other fast bowlers around the country make it feel a bit like the West Indies attack of the 1980s?
I saw the four-pronged West Indies pace attack when I was a very young man. I think Boult, Southee, Jamieson and Wagner are similar. It is a real testament to them as a group. They really work hard together. They talk a lot of things through. They have a lot of trust and bonding among themselves.
I think they are four different types of bowlers. A batsman is challenged by Kyle Jamieson's height and length, the swing of Tim and Trent, one being a right-armer and the other a left-armer, Neil's ability to adapt between being an aggressive hit-the-wicket bowler and constantly improving as a swing bowler. They certainly bring four very different challenges, which puts a lot of pressure on the opposition batter.
How does Mitchell Santner fit into this bowling attack, especially at home? Do you work a lot with him as well?
During the first innings of a Test match, he can certainly flick the switch between providing a period of support when the bowlers need a rest and in the second innings when there's a bit of turn. He is extremely accurate, which is why he has had his success.
I was really impressed by his role in our Test win over Pakistan [in December last year]. It was late in the game and we really needed him. He bowled very well.
I think he has a very important role. I get a lot of support from head coach Gary Stead and Paul Wiseman with the spinners, as it is a big job with a number of different bowlers.
New Zealand's pace stocks are probably at an all-time high. How do you assess the spin department? Santner is No. 1, but do you see it as a bit of a concern looking ahead to the T20 World Cup?
There are no concerns about the spin stock. We have quite an established bowling group. A number of players have put their hands up for a while. We have had Ish [Sodhi] and Santner. They have been really good T20 bowlers over the last two years. Todd [Astle] has taken his opportunities and done well.
In domestic cricket, we have also had success with a number of young players. We have had success with Will Somerville and Ajaz Patel in the Tests in Abu Dhabi against Pakistan in 2018.
During the season, Stead singled out Scott Kuggeleijn for special praise after he filled in as the hit-the-deck bowler for Lockie Ferguson. Similarly there was praise for Blair Tickner. But they were relegated to the bench again when the main bowlers returned. How do you deal with those bowlers on the fringe?
I think it is a real credit to the players themselves for coming in and executing the role given. They understand the situation, having been brought in when players are injured or rested. The guys take it really well. They look to do everything that supports the team. Credit also goes to the system in place that supports the players.
Where do you rate the New Zealand pace pack currently, compared to India, England, Australia and Pakistan?
The New Zealand bowling unit has been consistent for a number of years in all the formats. We pride ourselves in being a threat to the opposition regardless of the situation of the game. We want to focus on being a threat to all teams. We are trying to be consistent all the time, challenging ourselves and pushing our limits as a bowling unit. If we keep improving, we can be a threat to all teams around the world.
"The systems in place, not just around the team but also in selection, have been a strong asset for this side"
How much of your coaching is data-driven and how much is experience-driven?
We look to use the combination of data and our experiences together with the players' strengths. Data is always useful and we use as much as we can. If you only have a small amount of information, that's not really useful unless it is something that really stands out.
I think that's the key with data. You want to pick up on trends and match-ups and anything that really stands out. You balance it out with your experience and the skill set of the bowlers and what we are trying to achieve as a cricket team, and formulate it into one package.
What would you say are your top three matches from your time as New Zealand bowling coach, ones where you were really proud of the work put out by the pace attack?
I think three games stand out straight away.
First is the 2019 World Cup semi-final against India. It was a unique situation played over two days due to rain interruptions. We had some specific plans and options for the bowlers. I was just really proud of the way they adapted and really challenged India in defending a 240-odd total.
The second game is the home series against India in 2020. They are a superb cricket team over a long period, so to defeat them 2-0 in the Test series was amazing. Particularly in the second match, in Christchurch, we executed beautifully for two innings. It is a very special memory.
The third one goes back to the 2010 T20 World Cup, against Pakistan in Barbados. I think Pakistan needed two runs to win and we took the wicket off the last ball. It was just a heart-stopping thriller of a game. It was a hard-fought victory. Little things that happened throughout that game and how the guys just hung in there. They put pressure on Pakistan and got over them by just one run. Back then I was just a young bowling coach who had worked a couple of years at the international level.
How much has your experience with Bangladesh shaped your general point of view as a coach?
Coaching in Bangladesh gave me such amazing and valuable experiences. It gave me a different angle, and respect for the international game. I saw the game from a different point of view, in terms of the different styles of the players that I was working with.
It was extremely helpful in my development as a coach. I really enjoyed the successful times there. The guys were very talented and worked really hard to overcome so many different backgrounds to become international players.
How do you think have you grown as a bowling coach?
Mike Hesson and Gary Stead trusted me, empowered me, and gave me the opportunity to develop a bowling programme. It is an honour and a special opportunity for me to have such a flexible work environment where I can develop the bowling plans. I am working closely with Kane and the senior bowlers to develop systems and programmes around our bowling.
I get to work with bowlers at a number of different levels, which means I get to know them before they are in a position for selection for international cricket. It has helped me to develop good working relationships over a long period. It is such a privilege.

Mohammad Isam is ESPNcricinfo's Bangladesh correspondent. @isam84