When Brendon McCullum led the Blackcaps through a glorious patch of relative Test cricket success, Trent Boult and Tim Southee formed a formidable new-ball partnership. This was the same partnership that had featured for Northern Districts through various age group teams, then the New Zealand Under-19 team and then Northen Districts in the Plunket Shield with Boult swinging the ball back into the right-handed batsmen from his left arm, while Southee nipped the ball away with his right arm.

The Blackcaps enjoyed success during this period as a new-found dose of funk with the bat was enabled by the fact that Southee and Boult had their opposition reeling with early wickets more often than not. They made strong cases to be known as the best new-ball pair, especially in kiwi conditions and that they were dominating via the beautiful art of swing bowling only made it that much better.

Everything was great at that time and the future was looking bright as Southee and Boult were destined to keep swinging that red nut for at least another five years. What has happened since that purple patch though is of a major concern as instead of getting better, building on their success and giving the likes of James Anderson and Vernon Philander a run for their money as the best seamers in the world, Southee and Boult have trended in the opposite direction; yup, instead of getting better, Southee and Boult have got worse.

That the Blackcaps have endured a horrible 2016 while Southee and Boult's struggles have reached a peak, is no coincidence. The batsmen have definitely shown an Australian-like inability to grit their teeth and see out good spells of bowling from their opposition, yet the safety net offered by Sothee and Boult is no longer there, exposing the fragilities of this batting line up that could once play with freedom.

2014

Southee: 9 Tests, 33 wickets @ 26.03.
Boult: 9 Tests, 34 wickets @ 28.58.

2015

Southee: 8 Tests, 29 wickets @ 37.75.
Boult: 8 Tests, 36 wickets @ 31.47.

2016

Southee: 6 Tests, 14 wickets @ 46.14.
Boult: 9 Tests, 26 wickets @ 36.57.

For whatever reason, Southee and Boult have gone backwards, although those 2016 numbers are slightly skewed by Test matches in Zimbabwe, South Africa and India. That my friends only places greater intrigue on this two Test series against Pakistan as Southee and Boult will be back on home soil, bowling to Pakistani batsmen who - like their Indian, Sri Lankan and Bangaldesh homies - traditionally struggle with Aotearoa's conditions that are favourable for seam/swing.

The strengths of Southee and Boult line up nicely against the perceived weakness of Pakistan's batsmen. Pakistan however got us all on board their wagon with a fine performance in England and an experienced batting crew of Misbah ul Haq, Younis Khan, Azhar Ali, Asad Shafiq and Ahmed Shehzad are well equipped to implement plans that could limit the effectiveness of Southee and Boult. Even 20-year-old Sami Aslam who is likely to open the innings, scored two half-centuries in four innings against England.

In theory, Southee and Boult should rectify all of this and dominate Pakistan's batsmen with the moving ball, on juicy pre-Christmas pitches in overcast conditions. The alternative however will result in the Blackcaps relying on Neil Wagner to bounce the Pakistani batsmen out and this will leave us all pondering a weird predicament; are Boult and Southee doing enough to maintain their positions in a top-strength team?

Funnily enough, the horrible trend of these two coincides with the seam bowling stocks of Aotearoa continuing to grow - in quantity and quality. Wagner has already leap-frogged Southee and Boult as the bloke who gets kiwi cricket fans the most excited, while Matt Henry is lurking, waiting for an opportunity to string a few Test matches together. Doug Bracewell is in the mix as well, without really demanding further selection with his performances for the Blackcaps but he's there or there abouts and when you consider that Ben Wheeler, Ed Nuttall, Kyle Jamieson, Jacob Duffy, Lockie Ferguson, Mitchell McClenaghan, Adam Milne, Scott Kuggeleijn and Matt McEwan are all either simmering away in domestic cricket or will be looking to bounce back from injury strongly, there's plenty of competition here.

Competition for places though is more a sign of Southee and Boult's woes, than other bowlers really demanding selection. Southee and Boult have slid back into the pack instead of other bowlers in The Stable leaping out to meet them.

A very weird idea that could also come into play are the all-round abilities of Corey Anderson, Jimmy Neesham and Mitchell Santner (Kuggeleijn goes alright with the bat as well). If Anderson, Neesham and Santner are all healthy and their performances are worthy of selection (they are at the moment) then we need to start figuring out a way to fit all three into the same team. This could present a situation where Wagner and Henry for example are joined by Anderson and Neesham as a seam attack, while Santner offers spin.

The ability with the ball of Anderson and Neesham could put some low key pressure on Southee and Boult, especially if they can do a decent job with the ball as they would from a bloody handy lower order and extend the batting line up.

For now though, Southee and Boult have an opportunity to set things right. They are currently trending in the wrong direction and a home series against Pakistan smacks you in the face to flip that trend and get it going in the right direction, given the quality of Pakistan's batsmen though, I'm cautious.