Ashes captains, Cook and Clarke, set for key series

They've both played 92 Tests, they are both world-class batsmen and they both scored a hundred on Test debut, in each case away to India.

But it's the differences between England captain Alastair Cook and Australia skipper Michael Clarke that promise to make their personal Ashes battle particularly fascinating when the latest clash between Test cricket's oldest rival nations starts in Nottingham on Wednesday.

For while both men like to lead by example with the bat, Cook is seen as a popular leader, capable of handling 'awkward' characters such as Kevin Pietersen, but a cautious tactician whereas Clarke is regarded as imaginative in the field but has faced questions over his man-management.

Aged just 28, Cook has already scored more test hundreds -- 25 -- than any other England batsman.

He took over as full-time captain when Andrew Strauss, Cook's old opening partner, retired after last year's home series loss to South Africa.

Left-hander Cook then struck three hundreds as England achieved a rare series win in India.

But during a subsequent drawn series in New Zealand, Cook's field placings seemed overly defensive when compared to those of home skipper Brendon McCullum.

In the return series against New Zealand earlier this season, England won both matches for a 2-0 series victory.

However, in the second Test in Leeds, with rain forecast, Cook delayed his declaration until New Zealand had been set an improbable 468 to win and then denied off-spinner Graeme Swann some close catchers.

In the end, England dodged the showers and won by 247 runs.

"It is very easy when you are sitting behind the rope to say, 'I would have pulled out with 350 on the board'," Cook said afterwards. "You are judged as a captain on results...I think the result vindicates the decisions."

England's approach in the field under coach Andy Flower has been one of keeping control and building pressure.

But former England captain David Gower, writing in the Sunday Times, said: "Those of my generation tend to feel that more can and should be done to add further pressure with more men around the bat -- at the right times -- and that too often opportunities to do so are allowed to pass.

"The fact (India's MS) Dhoni, McCullum and Clarke are prepared to make those moves tells me....that even in this era captains can and will be imaginative and bold -- if they allow themselves to be," added Gower, an Ashes-winning skipper back in 1985.

Since January 1 last year, Clarke has been in superb form, with a triple hundred against India and three more double centuries, including two against South Africa, the world's leading Test side.

Yet his batting and attacking captaincy could not prevent a series loss to South Africa or a 4-0 hammering away to India, where his backing for coach Mickey Arthur proved divisive.

Arthur was eventually sacked just 16 days before the Ashes, following the 'homework' row that saw four players, including then vice-captain Shane Watson, dropped for not completing a written assignment.

Clarke also found himself criticised for not spending enough time with his team during the early stages of the tour of England when he was receiving treatment for a longstanding back injury.

In his absence, Australia batsman David Warner was banned until the first Test for his Birmingham bar room attack on England's Joe Root.

However, the fact that Darren Lehmann has since replaced Arthur and that the captain himself is no longer a selector should help Clarke, whose 'celebrity' off-field lifestyle has not always endeared him to team-mates and fans alike.

England hold the Ashes and that makes it less likely Cook will depart from his usual approach.

A poor series with the bat for either captain could affect the morale of their team while, conversely, Australia's batsmen could do much to ease the burden on Clarke by weighing in with big scores before the No. 5 takes guard.

"We can't leave it all up to Michael," said opener Chris Rogers. "There's a role for all of us, particularly in the top order."