Stuart Broad's neck is tightly wrapped in a grey scarf as he bends his lanky frame through the dressing-room door at Trent Bridge and apologises in advance for his man-flu. It is the first week of March and he has been back in the frozen north for a matter of days, having concluded another seminal Test series in South Africa with an extended stay for the one-day leg of England's tour.

The change of climate, he says, has got to him, although there's little evidence of it in his voice as he sits down near his locker in the corner of the pavilion and sets about recounting the tale of his recent rise and rise. Broad has finished England's winter as the No. 1-ranked Test bowler in the world, a stature that is not misplaced. Of his burgeoning tally of 333 Test wickets at 28.66 in 91 appearances, 69 have come in the past 12 months alone.

His role in South Africa's 2-1 series defeat was typical of his recent impact on Test cricket. Broad's 18 wickets encompassed two outstanding match-changing spells - a haul of 4 for 25 in his first innings of the series in Durban, as England wrestled control of a contest that could have tilted either way, and then, three weeks later in Johannesburg, the latest of his patented game-wrecking displays.

Six wickets for 17 runs came in the final analysis, and 5 for 1 in 36 balls at the height of the carnage, as Broad bounded in with the élan of Curtly Ambrose, no less, to turn what had promised to be an anxious battle of wills into a rout. England, who had trailed by ten runs on first innings, had been bracing themselves for a fourth-innings target in the region of 250. Instead, on the back of Broad's efforts, they clobbered their way to a series-sealing 74 inside a single session.

"We played some brilliant cricket in that whole series," Broad recalls. "We won those key moments, which we've done in a couple of Ashes series as well, and then [in Johannesburg] we had one of those perfect bowling days to really ramp it up. There was pace in the wicket, there was bounce, seam, it swung a bit, the lights were on. I'd take that wicket with me everywhere."

He'd take it everywhere, you suspect, except to his home ground. For it was on the pitch down below us, in the fourth Test of last summer's Ashes, that Broad produced the spell for which he is destined to be remembered. ESPNcricinfo's Test bowling performance of the year would surely be a contender for the most startling of the decade. Eight wickets for 15 runs in the space of 9.3 extraordinary overs; Australia hustled out for 60 on the first morning of the match, their hold on the Ashes effectively ended in little over an hour's play.

We venture briefly out into the middle to film the presentation of Broad's Test bowling trophy, and set up the camera on more or less the spot, some 30 yards in from the pavilion boundary, where his run-up that day would have begun. It's easy enough to be transported back to the events of that extraordinary morning, which began - lest we forget - with England fretting over the damage that James Anderson's side strain had done to their Ashes prospects.

Broad, however, made it his personal mission to paper over that apparent crack. "I really like that added pressure," he says. "That's something that really floats my boat. I like it when the captain comes to me and says, 'We're really desperate for a wicket, can you get us one?' or when we really need something to happen in a Test match. I'd rather be the guy you can turn to in a high-pressure scenario than a dead rubber."

And he has now fronted up too often at the critical moments for his impact in such contests to be dismissed as a coincidence. Broad's Johannesburg rampage was the seventh time in his Test career that he has taken five or more wickets in a single spell, and not once on those occasions had his impact been anything less than pivotal.

Three Ashes-sealing onslaughts in each of the decisive Tests of the last three home series against Australia, in 2009, 2013 and 2015; a trio of series-turning spells against India in 2011, New Zealand in 2013, and South Africa last month, and finally - just to prove you can't win them all - a five-wicket burst against the then-No.1 ranked South Africans that gave England an outside chance of saving their bacon at Headingley.

"It's enjoyable when it happens," Broad says. "It's something that gives me an extra buzz, it spurs me on and really gets my tummy excited. I love those moments when it's time to step up. My favourite spell of all would have to be the one at the ground we're sat at now, but away from home it's the Wanderers, for sure."

The sense of inevitability when Broad now gets on a roll is proof both of his burgeoning status in the world game, but also of his own big-game mentality - something that Michael Vaughan remarked upon way back at the start of his Test career in 2007-08, when the then-England captain claimed that Broad was "the most intelligent bowler I have ever worked with".

The man himself is now sufficiently attuned to his own rhythms to recognise how to sustain these moments when they come, but he credits Peter Moores, the former England coach, for nailing the tactics required to make the most of his hot streaks.

"When he was England coach, he really spotted that when I was defensive or putting fielders out, I didn't have the same snap through my action. Mentally, he really encouraged me to set attacking fields because that puts me under pressure, and he realised that I need to be under pressure to perform. Put a short leg in, put four slips in, because then you can't bowl a half-volley because if you do you'll be hit for four. He found a way for me to put myself under pressure, which generally improves my performance."

As for the internal mechanics, that is simply a matter of putting a decade of experience to good use. "I try to look for tempo in my run-up to make sure my knees are lifting up instead of going long," he says. "That brings an energy to my run-up, try and make myself feel as tall as I can.

"It's a balance because, in the spells when I've taken my wickets, I'm not trying to bowl too hard, I'm not trying to bowl too quick, or bowl inswing or outswing, I'm just keeping it simple. It's about lifting my knees up, running in with a tempo and energy, and looking to take wickets all the time. Of course, it's not going to happen every time, but the consistent thing every time I've had these spells is the wicket-taking mentality, the energy in my run-up to hit the crease hard."

The transformation of Broad's status has been so gradual that many still find it hard to give him the credit he deserves. For much of his early career, his place in the team was arguably based on potential as much as performance - remarkably for a fast bowler, he has missed just 13 Tests out of a possible 114 since his debut in Colombo as a 21-year-old in 2007, and four of those came when he tore stomach muscles on the Ashes tour of 2010-11.

But in more recent years, the value of that investment has been paid back in spades. Between them, Broad and Anderson have now racked up 631 wickets in 83 Tests as a partnership - the fourth-most prolific pairing of all time - but, at four years the junior man and on the eve of his 30th birthday, Broad knows from the example at the other end that his very best years could yet come.

"When I was younger, a lot of people said your best years as a bowler come between the ages of 28 and 33, so that excites me in the fact that I've still got a lot to go," he says. "You only have to look at how Jimmy Anderson has improved in the last six years.

"I try not to look too far ahead but I do feel as fit as I've been," he adds. "Part of getting better between ages of 28 and 33 is you know your body better, when to push it and when to hold off a bit, and I do feel like I've got a lot of cricket left in me.

"Four hundred wickets would be an absolute dream but, with the amount of cricket we play these days, that might not be far off. I've played for a long time, you never know what will catch up with you if you bowl a lot of overs when you are younger, but Jimmy is going all right, isn't he? I don't want to put a cap on it because I want to play as long as I can at the top level, but I know a lot of hard work comes into that."

For the time being, Test cricket is Broad's primary focus. He retains ambitions of playing in the 2019 World Cup on home soil [see sidebar], by which stage he would have just turned 33, but he knows that he has plenty to be getting on with in the meantime, simply to live up to his No.1 Test billing.

"I need to keep moving my game forward, because Test batsmen will keep moving their games forward," he says. "You are always learning, listening, working with bowlers in the nets, and with the bowling coaches as well. I actually opened the bowling with Ottis Gibson at Leicestershire, so we are great friends, which really helps, and I owe a lot to David Saker for the way he changed my mind tactically. He wasn't a big technical coach but tactically he was world-class. He made me quite a mentally strong bowler, I think.

"I've put a lot of hard work into bowling to left-handers in the last two years as I felt that was a big weakness of mine, but I'll keep searching and keep improving, because we go to India at the end of this summer and you need some different skills there as well."

And with that, Broad picks up his trophy and strolls off across his outfield, back into mothballs until the summer campaign gets underway, when Sri Lanka and Pakistan arrive for the 2016 season.

"We have seven of the nine Test trophies available to us," he says as a parting shot, "and those are the ones that we don't have, so what an incentive for us as a group of guys to go and win every Test this summer, entertain the crowds that support us so fantastically in England, and try to get those nine trophies."

Andrew Miller is UK editor of ESPNcricinfo. He tweets @miller_cricket