Ashes: 'England must find consistency or international careers will be on the line'

I said both before the Ashes series began and then again after England lost in Brisbane that the second Test, the day-nighter in Adelaide, was their lifeline.

The pink ball, the floodlights and conditions that seemed ideal for their bowlers were a wonderful opportunity for them to win a Test, level the series and maybe build a platform from which to retain the Ashes.

For half of the match, they proved me right. The problem is, that half was the second half and they were already too far behind.

In football parlance, it was a game of two halves - and England were 3-0 down at half-time. By then, their big chance had been blown.

If they had the energy and vigour with the ball that they showed in the second innings in the first, or they had batted better in their first innings, then who knows what might have happened.

As it turned out, they were left with trying to come back from 215 runs behind, a huge margin, and, even though we dared to dream something special might happen on the final day, we know there was no more than a 20% chance of an England win.

Sure enough, Australia powered to a 120-run victory and England have the disappointment of a 2-0 Ashes deficit.

After the match, coach Trevor Bayliss said that England's batting is his biggest concern - his side have not managed a total in excess of 302 in four attempts in this series.

For so long we have witnessed periods of England self-destructing, of playing inexplicable strokes and bringing about batting collapses.

Here they were 142-7 in the first innings and I still can't put my finger on why it keeps happening. I sit there scratching my head like everyone else. I'm sure Bayliss and captain Joe Root do too.

You wonder why a certain batsman has played a certain stroke, or fallen into an obvious trap.

Whether you are watching from a commentary box, listening on the radio, sitting in the stands or keeping an eye on the telly, we are all bewildered together.

Somehow, they have to learn a lesson they have now been taught twice by Australia - by Steve Smith in Brisbane and in Adelaide by Shaun Marsh - of how you work hard to score Test hundreds.

Both Bayliss and Root said in the aftermath of this defeat that they believe their players are good enough, that the periods in both Brisbane and Adelaide in which they competed strongly with Australia proves as much.

I don't believe those words are untrue, or that they are trying to pull the wool over our eyes.

The question is, though, which is the real England?

Is it the one competing with Australia for a half a Test, or the one being dominated for half a Test?

To me, when England are matching the home side, they are playing at their true standard. They have shown the level at which they can play, but the failure is that they are unable to do it for long enough.

That then leads us to what is perhaps the bigger issue: how does a player make the step from producing fleeting moments of the right quality, to prolonged periods of Test-quality cricket?

You can have the talent, but you have to have the confidence to believe you are good enough. Having that belief is a huge step.

For a developing player, of which there are plenty in this England side - Mark Stoneman, James Vince, Dawid Malan, Craig Overton, there will be ups and downs along the way. It is unrealistic to expect consistency right away.

Even then, the most established players can have times when they perform below their best. James Anderson bowled beautifully in Australia's second innings to pick up his first five-wicket haul in this country, but he should have done it two days earlier.

It is therefore up to England - and when I say England, I mean the players, rather than the staff - to find that consistency for the rest of the series.

If they don't, then their international futures will be on the line, just how Australia spinner Nathan Lyon wanted it to be before the series began.

Even if England can repeat the required level of performance for the remaining three Tests, it will be incredibly difficult to come from 2-0 behind - no England side has done that in an Ashes series before.

Root says his side are "massively in the series". I'm not sure about that, but there are certainly differences from this side to the one whitewashed in 2006-07 and again in 2013-14.

One is Root himself - a young, ambitious, hungry captain leading a group of like-minded players trying to prove themselves. He's respected by the players and is a steely character.

Now, in what is an enormous test of his captaincy, he has to show leadership.

Can England avoid the defeat in Perth that would hand Australia the Ashes? History is against them, having not won at the Waca since 1978.

Their bowlers must not get carried away with the pace and bounce and instead bowl a full length and target the top of off stump. The batsmen must give themselves time to get used to the conditions, not play the rash stroke that has them back in the pavilion before they have settled.

They need focus and discipline over the five days.

Still, it would be a surprise to me if England win in Perth.

Jonathan Agnew was talking to BBC Sport's Stephan Shemilt.