Ryan Harris knew THAT ball carried the potential for something special from the moment he settled into his approach, well before it left his hand bound for cricket folklore.

In his mind, he could see the path it was to take.

Settling into stride, index and middle fingers resting lightly either side of the ball's hard raised seam, Harris glanced fleetingly at the freshly-painted crease lines then lifted his eyes.

Not to a specific spot on the pitch where he aimed to land the ball. And not for long on the batsman who waited perfectly still, bat raised in anticipation and squinting slightly – concentrating hard – in the blazing midday sun.

Instead, his focus was on getting it through at sharp pace and decent height to 'keeper Brad Haddin.

At release Harris knew where the ball was headed, but held no clue as to how the atmospheric conditions, the revolutions of backspin imparted with a snap of his wrist, or the impact of the raised seam on the minute variations of grass cover and surface cracking would have on the line it took to reaches its destination.

From the instant it left his hand, Harris sensed that all the planning, all the visualisation, all the hoping had come together with the sort of opening delivery of an innings that can define a career.

Bowler's or batsman's. Just ask Shane Warne or Mike Gatting.

"I'm trying to bowl that one every ball," Harris recalls of the first delivery he sent down to Alastair Cook at the start of England's second innings of the third Ashes Test in Perth that flipped the bail from the skipper's off stump and the lid on Australia's expectation of regaining the urn.

"I actually felt really good before that ball. I felt really switched on, it was a big innings and it was a big time of the game.

"My run-up felt good, the action felt really strong and it came out nicely. I knew it was close from the time it bounced, but I didn't see it hit (the stumps). I just saw the bail go."

At 34, Ryan Harris has been a new-ball bowler for as long as he can remember. With a couple of exceptions that you suspect still rankle.

Like the memory of his first fourth-grade match for Adelaide grade club Salisbury, in which he batted at No.9 despite playing much of his junior career as predominantly a batsman, and where he took the ball as third-change bowler.

Having seen what he was capable of with the aged ball, his skipper then decided the young bloke might not be a bad option with the new one come the second dig.

"I took five-for in seven overs," Harris muses. "He said to the guys 'Why didn't you tell me he could bowl?' and their answer was 'Well you're the captain, you're supposed to know'.

"Probably from then on I became an opening bowler."

And since Michael Clarke told him he was to take the ball for Australia's first over in the third Ashes Test in Manchester in 2013, Harris has been the man entrusted with setting the tone for his country's bowling effort.

It's a responsibility that weighs comfortably on his broad, brickie's labourer shoulders.

His preparation leading into that moment when he stands atop his mark, the crowd noise builds, the batsman settles into his stance and the officiating umpire says simply 'play' is as pragmatic as you would expect from a bloke whose career has been the inverse to those who peak young and take success for granted.

For the current series, it began with him tuning into the evening television coverage of South Africa's two-Test series against India late last year, when the Ashes were securely in Australia's keeping.

Harris doesn't like scrolling through edited highlights packages, preferring to watch the game live so he can analyse the lead-up tactics, the set-ups that fielding teams employ to get batsmen out.

Then it's the 'out' balls that he zeroes in upon.

"I made sure I sat down and watched each individual South African batter for a certain period, and I looked at how India bowled," Harris said, hunched forward, eyes trained on the empty coffee cup that rests in front of him at the Australian team's surfside hotel in Port Elizabeth.

"If I look at footage I really only look at how they get out, the ball that gets their wicket.

"I know, having seen it on television, where most of their guys score. For example I know that Graeme Smith is a big on-side player so I've got to get him driving on the off side.

"(His opening partner Alviro) Petersen loves the short ball, and (No.3 Hashim) Amla is again big on his pads, so no width to him.

"For me it's all about dismissals and looking at where to put the ball, where their weaknesses are."

The intelligence gleaned from watching and getting a 'feel' for how particular batsmen look to counter specific types of bowling didn't take long to find its way into the bowlers' confab held prior to the squad leaving Australia, or the team meetings scheduled for two days prior to each Test.

That was obvious from the way Smith was dismissed in the second innings of the first Test at Centurion.

Clipping a full delivery from Mitchell Johnson that angled into his pads sweetly but in the air, and which was stunningly plucked about knee high by Alex Doolan who had been purposely placed in a non-traditional leg-side catching position that was a kind of deep short leg. Or short leg gully.

"That field we set for Smith in the second innings, that was something a few of the guys picked up (from the series) against India," Harris revealed.

"It was almost a leg gully, whereas India had him a bit deeper, but Michael (Clarke) knew where he wanted him and it was the same sort of field."

While cricket is often clichéd as a game of inches, it is more often a game of instinct which is why those sorts of plans can work time and again.

Batsmen have spent a lifetime building a technique around the shots they feel most comfortable with and are most adept at playing, so changing that when a bowler comes up with a counter plan can take a long time, and require lots of mental re-configuring.

Harris also adheres to the 'train as you play' mantra, and while bowling with a new ball in the practice nets against left-handed openers Chris Rogers and David Warner he will aim to land the sort of deliveries he'll be employing against fellow southpaw Smith a few days hence.

Come day one of the second Test at Port Elizabeth, Harris will have bowled sufficient deliveries in training to know within himself that he's feeling good, but not so many as to leave him feeling overworked.

That varies between three and six overs two days out from the Test. And neither he, Mitchell Johnson or Peter Siddle like to bowl at all the day before.

No point in leaving your Alastair Cook ball in the nets.

He'll get to the ground early so he can perform his warm-up unhurried; a light jog before the masseur and fitness gurus push and stretch any sore spots.

A run through of his bowling action, complete with another brand new ball, that begins slowly and builds to a full match-time replica to gauge conditions, breeze and local centre-wicket characteristics.

He'll use the tape measure to mark the two crucial points of his run-up – 18.4m from where he breaks into a run and 16.2m where he settles into stride.

Stepping out his run-up and marking it with a metal disc is another of those quaint old relics he left behind when he moved from Adelaide to Brisbane.

But he won't spend much time examining the pitch.

"Maybe two or three days before we'll take a look at it but I don't really take too much notice of it," Harris says.

"The only thing I'll do is maybe take a look and see if there's any cracks – like the other day (at Centurion) where some started opening up during the match.

"We walked out on day four and Mitch (Johnson) measured them out to see where they were in relation to length and line, so then I know in the back of my mind that if I hit the right spots the cracks are going to help me."

Nor does he pay much mind to the coin toss.

While the chance to have first go at a new pitch, with a new ball against a new batsman is what fast bowlers live for, Harris also appreciates that a captain winning the toss, batting first and having his team post a score of 400-plus is the surest way of winning Test matches.

If it's a bowl-first day, there is one decision he knows has been pre-ordained. At least since the 2013 Ashes series in England.

"Michael (Clarke) has given me the first ball ever since Old Trafford, so for the past six to eight months I've had it.

"Sometimes, with Mitch bowling the way he is, I think he's going to get it.

"But I think Mitch gets the choice of ends, which is usually anything downwind because he's express (pace), so I get to bowl the first ball.

"I don't care which end I bowl from – I've got no choice. Because I know if I don't like it I won't play."

He'll settle into the top of his mark, place the ball carefully in his right hand, and decide what sort of delivery he's going to serve up.

He hopes it's not the loosener that he dragged down to Smith at the start of the first Test at Centurion, against which Smith stood tall and dismissed through mid-wicket for four. An instant pressure release.

It might be a bouncer, simply because the batsman won't expect it – though Harris knows he needs to target it at his opponent's head rather than his chest where it's too easy to counter.

Or on the balance of probability, in that nasty not-quite-full length with a hint of late swing that commits the batsman to a stroke and then finds sufficient deviation from the pitch to take it past the bat. But not so much as to miss the edge, or the stumps.

In other words, THAT ball.

"That's just a dream ball," he says, his smile broadening.

"As a quick, to bowl one that swings in, nips away and hits the top of off – that's fast bowling to a tee.

"That's what you try and teach young kids. But it's bloody hard to do."