England's Jekyll and Hyde act keeps everyone guessing

England go into that deciding game in Tasmania on the back of a morale-boosting win which offered a glimpse of their considerable potential.

When everything clicks, they are a dangerous side. When it doesn’t, they are a danger to themselves.

Matters, of course, must be placed into context.

England posted their highest one-day score in Australia – 355-6 – against a host country which had rested some key bowlers ahead of the New Zealand Test series.

There is no Pat Cummins, no Josh Hazlewood and no Mitchell Starc. Nathan Ellis, meanwhile, is out with a side strain.

Mahli Beardman, whose 6-24 in the seven-wicket win in Perth were the best figures by an Australian on one-day international debut, was rested for this match as the hosts took no chances given his history of back injuries.

Beardman is expected to return for the fixture in Hobart – England’s fourth successive bilateral ODI series to go to a decider (they won the other three).

Riley Meredith, who replaced Beardman, was Australia’s most expensive bowler with 1-75 from 10 overs. Still, the old cliché that you can only beat what’s in front of you is a cliché for a reason.

England hammered Australia by 135 runs, bowling them out for 220 inside 45 overs in a run chase in which the word ‘chase’ was largely superfluous.

Their own huge score had been built on four major contributions: Tom Banton’s 121 from 99 balls, Jordan Cox’s 67 from 49, Joe Root’s 62 from 68, and Will Jacks’s 54 not out from 40.

It was particularly encouraging that Harry Brook failed – ditto Ben Duckett – and yet England still went where no England side had gone before in Australia, eclipsing their previous best one-day total Down Under of 333-6 at Sydney in 2011.

On that occasion, the Aussies hit back to win by two wickets. This time, however, there was never much prospect of a repeat, with Gus Atkinson quickly reducing them to 29-4 with some excellent bowling: full and straight.

Cameron Green (64 from 82 balls) and Matt Renshaw (63 from 74) were the only pair to offer much resistance, putting on 98 from 114 deliveries for the fifth wicket.

Green’s dismissal rather summed up the night from an Australian perspective.

A ball from left-arm spinner Liam Dawson missed the bat, struck wicketkeeper Cox on the pad and bounced forwards on to the stumps, with the batsman out of his ground.

The only blemish on England’s performance was a handful of dropped catches: some straightforward, others less so.

Still, there was an energy about them in the field, a sense of purpose that was impressive given the rude awakening they had suffered on Friday.

The lack of turnaround time, coupled with a 1,400-mile flight, had given them precious little opportunity to regroup.

Such is the way of it these days with these ten-a-penny series and the jam-packed schedule, which barely gives anybody time to draw breath.

It only seems five minutes ago that England were in Pakistan, displaying the less attractive side of their character in a disappointing tri-series performance.

Next Saturday, they begin another white-ball series against Australia – this time T20 – and soon enough will be playing Test cricket in South Africa.

The mind boggles.

Still, it was a red-letter day in the City of Churches – not least for the burgeoning Banton.

His recent form has been so good that the injured Jacob Bethell will surely have to make his return lower down the order.

Cox, too, has seized his chance in the absence of the injured Jos Buttler. England have options – which is no bad thing as the countdown to the World Cup continues apace.

Banton is an engaging player to watch: powerful, but with plenty of polish.

There were four sixes in his innings to go with 12 fours. He hits an elegant ball as well as a long one.

England were undone by the bounce in Perth – aren’t they always? – but found conditions in Adelaide more to their liking.

That they are as likely to go to Hobart and hammer Australia as to get hammered themselves, however, seems to be an inescapable fact of life.

England’s catching was not at its best, but Root pulled off an absolute screamer.

When Mitchell Marsh flashed hard at Sonny Baker, Root flew high to his left at first slip to take it two-handed. Not bad for a man who turns 36 next month.

One who turns 39 in February, Adil Rashid, is still warming the bench behind Liam Dawson.

Dawson did alright – 9-0-41-2 could be the sort of figures they put on his tombstone – but he lacks the X-factor provided by the leg-spinning Yorkshireman (the term ‘Yorkshire leg-spinner’ no longer applicable).

On to ‘Tassie’, then, also known as The Apple Isle, or The Holiday Isle.

Which England will turn up?

Answers on a postcard.