ALASTAIR Clarkson was still ambitiously climbing the coaching ranks when he made a decision that might have been the difference in him becoming a Hawk or not.

The year was 2003, and Clarkson was back in the AFL system as an assistant under Mark Williams at Port Adelaide.

He spent the previous three seasons coaching VFL team Werribee then Central District in the SANFL, leading the latter to the 2001 premiership.

Clarkson's desire to continually upskill himself led to him attending the AFL High Performance Level Three coaching course in Canberra, which coincided with the draft camp.

None of that is unusual, until you discover that Clarkson wasn't enrolled in the course – and caught a plane to the nation's capital not knowing if he would get in.

There was no level three coaching course in 2002 and it was the only one a year later, run by the AFL's then-coaching development manager Lawrie Woodman.

"Knowing Clarko, I'm pretty sure he would have thought he'd be able to get his way into the course, but it was a punt," Woodman told AFL.com.au with a chuckle.

"He turned up unannounced and said, 'I'm Alastair Clarkson; I'm here to do the level three course'.

"I was a little taken aback, but I was like, 'Oh well, if he's that keen and he's ready to go' … we included him and he was very good."

What makes this five-day course so significant is that Clarkson was Hawthorn's new coach a year later, having performed a key role behind Williams in the Power winning the 2004 flag.

It is not unheard of, but rare in this day and age for anyone to win an AFL head coaching job without completing the level three accreditation.

James Hird and Don Pyke are among the exceptions to that rule.

The importance of that course to the Hawks' future doesn't stop there.

A man by the name of David Rath presented on the biomechanics of kicking, and wowed Clarkson so much he told his wife, Caryn, he would offer Rath a job if he ever became a head coach.

Clarkson, who turns 50 on April 27, was hired at Hawthorn 11 months later and one of his first appointments was Rath.

"I got a cold call (from Clarkson) and my wife was expecting our second child – she had three weeks to go," Rath said.

"We were pretty settled in Canberra at that stage, but it was an opportunity to do something I wasn't really expecting … and it was too good to not take up."

Rath was credited as the key plank in the Hawks going from the worst kicking side in 2004 – pre-Clarkson – to the best leading into and during their 2008 flag and the 2013-15 premiership three-peat.

Another of the coaches in that level three course was Clarkson's former North Melbourne under-19s teammate Anthony Rock, who is a Fremantle assistant these days.

Rock is not surprised with how successful Clarkson has become as a senior coach.

"He was a very determined person, even back then," Rock told AFL.com.au.

"He's a really tough person, he's gritty and is very knowledgeable, and whatever he set his mind to he was going to achieve.

"When you have premiership success like he has, it happens for a reason – and that's called hard work.

"He was always prepared to do hard work as a footy player, and that's translated into his teaching and coaching."