England v Australia, 2nd Investec Test, Lord's, 1st day July 18, 2013

A priceless inch for Bairstow

While it was galling for Jonny Bairstow to fall to a Steve Smith full toss, his innings had looked to have ended much earlier but Peter Siddle's overstepping have him a crucial second chance

It is remarkable how one moment of fortune can shape a career. A life, even.

Consider Nasser Hussain. He was recalled for his first Test in almost three years against India at Edgbaston in June 1996 knowing that another failure could prove fatal to his international aspirations. Those were the days long before the phrase 'continuity of selection' had become familiar in England cricket.

So when Hussain gloved one down the leg side early in his comeback innings, he must have feared the worst. Fortunately for him, though, umpire Darrell Hair, took a different view and Hussain survived. He went on to score his first Test century and cemented his place in the Test side for much of the next decade.

It is no exaggeration to suggest that, without that error from Hair, Hussain may never have become England captain and, as a consequence, might never have become part of the Sky commentary team. He might, even now, be stacking shelves in Tesco.

May Jonny Bairstow have been blessed in similar fashion at Lord's? Bairstow had 21 when, his balance unsteady and his focus not on the ball but on the direction he intended the ball to travel, was beaten by one that may have come back into him a fraction from Peter Siddle and was, for the sixth time in a Test career of 14 completed innings, bowled.

Except it turned out to be a no-ball. By the smallest margin possible it turned out to be a no-ball. And Bairstow was reprieved. He went on to register only his second half-century in his last 10 Test innings and add 144 with Ian Bell. In terms of both his career and the match, this was a crucial innings from Bairstow.

It is worth speculating on what may have happened had Siddle's front foot been a couple of millimetres further back. Bairstow would have been out bowled for the fourth time in five innings (to follow twice against in the warm-up against Essex and once at Trent Bridge) and questions about his form and technique would have grown.

So, too, would questions about the suitability of Joe Root to open the batting. Root, having now opened five times with Alastair Cook (three times in Tests and twice against Essex), has yet to make a 50 and, had both he and Bairstow failed here, there would have been calls to allow him to continue his development away from the new ball and at the expense of Bairstow.

That may have had consequences for Nick Compton, too. While the suspicion lingers that the England selectors have reached a verdict on Compton that bodes ill for his international future, there would have been a gathering case for his recall, possibly as a relatively short-term solution, to allow Root to return to a less pressured middle-order spot and provide the new-ball blunting role that England have yet to convincingly display in the series to date.

None of this means the selectors would have changed tactics - they surely would not have done so soon after adopting a new approach - if Bairstow had failed. But the pressure would have grown, the vultures would have gathered and the chances of succeeding may well have diminished.

This innings does not confirm Bairstow's arrival as a Test player. This is, at this stage of the game at least, an unusually flat pitch, his technical issues remain and his failure to go on and convert his start into a match-defining score was regrettable.

But it will help. It will buy him time, not just from the selectors but from the media, and it will give him renewed confidence. It was a significant step in the right direction.

This was still very much Australia's day. While a couple of England batsmen, not least Bell and Kevin Pietersen, could console themselves with the thought that they had received good deliveries, a couple of the others, not least Bairstow and Jonathan Trott, will reflect with bitter disappointment on the part they played in their own downfall.

On a glorious wicket for batting and against a strong seam attack, but one lacking much variety, they had an excellent opportunity to post a commanding total. But losing three wickets for 12 runs against a part-time leg-spinner who had, before today, all but given up bowling was weak. Anything under 450 in the first innings might be considered a wasted opportunity.

Trott, timing the ball sweetly, is clearly in sublime form. But his failure to cash-in on his good starts will frustrate him as much as it is his side. He has now been dismissed for scores of between 27 and 76 in 10 of his last 12 Test innings with a propensity to give it away after doing all the hard work becoming as regular a feature of his batting as it is unwelcome.

There was more encouraging news in the sustained contribution of Bell. He will face tougher attacks in tougher conditions but, as was the case at Trent Bridge, he came to the crease with his side in trouble in an atmosphere as intense as he will face in a home Test. His almost faultless innings - he reached his 50 with a slice that was not far from point - contained solid defence, no outward sign of pressure and, as he became more established, a succession of gorgeous strokes that spoke of a gift for timing granted to very few.

He is now, along with Hobbs, Hammond and Chris Broad, one of only four England players to have scored centuries in three successive Ashes Tests. His journey has encompassed in a few detours and taken a little longer than expected to reach its destination, but he has now become the player his ability always threatened to make him.

George Dobell is a senior correspondent at ESPNcricinfo