One seemed destined to be a Test captain at 23; the other was thrust into the leadership following an extraordinary crisis and not long after he'd thought of quitting cricket.

When England's Joe Root and Australia's Tim Paine walk out for the toss prior to the first Ashes opener at Edgbaston starting Thursday they will have taken very different routes to get there.

England used to put a premium on so-called 'leadership qualities', picking the captain ahead of the rest of the side, whereas Australia would select their best XI and appoint one of them as skipper.

But an increasingly congested international schedule, which deprives Test regulars the chance of sustained captaincy experience in county cricket, prompted a change in England's approach.

Neither Root, nor his predecessor as England captain, Alastair Cook, have been regarded as superb tacticians.

But as top-order batsmen, guaranteed their place in the side, they have been obvious captaincy candidates particularly as, unlike frontline bowlers, they don't have to worry about when to bring themselves on.

When Root took over in 2017, he had been a captain in just four first-class matches, one of which saw him dubbed "Craptain" by his Yorkshire team-mates after Middlesex chased down a target of 472.

Former England off-spinner Graeme Swann voiced fears that captaincy would have a negative impact on Root's run-scoring.

Root's responded with a match-winning 190 against South Africa at Lord's, in his first match in charge, and a century in England's first day-night Test, against West Indies at Edgbaston.

- Lead from the front -

But he went more than a year before again reaching three figures in a Test, a period that included a 4-0 Ashes series loss in Australia.

Now England will hope a return to number three allied to the responsiblity of leading from the front will improve the 28-year-old Root's conversion rate of fifties to hundreds (41-16 at present).

Paine's road to the captaincy was far more rocky and not just because of a belief that wicketkeepers already have enough to do in the field.

He was set to retire in 2017 and take a job with a cricket equipment manufacturer, yet by March 2018 he was Australia's captain.

Paine made his Australia debut in a neutral Test against Pakistan at Lord's in 2009 and he appeared the heir to Brad Haddin as the long-term wicketkeeper.

A finger injury blighted his career and there were times when he was not even the first-choice wicketkeeper for Tasmania.

But when rival glovemen Peter Nevill and Matthew Wade were dropped ahead of the 2017/18 Ashes, Paine made the most of his recall.

Then came the 2018 ball-tampering scandal during a Test in Cape Town, which saw then Australia captain Steve Smith and vice-captain David Warner given year-long bans by Cricket Australia for their roles in a flagrant breach of the rules.

Paine, now 34, was thrust into the captaincy to help instill values that would sit well with Australia's shocked fans, never mind opponents who had become weary of the team's crude 'sledging,' or verbal abuse.

Paine is the first captain chosen to lead an Australia Test tour of England primarily because he is a 'decent chap' since Ian Johnson in 1956 -- a series England won.

But given it's 19 years since Australia last won an Ashes in England, perhaps captaincy by macho posturing hasn't worked for them.

In the words of the late Australia captain Richie Benaud, a hugely successful and sporting skipper: "Captaincy is 90 percent luck and 10 percent skill, but don't try it without that 10 percent."