When did the world change? On January 23, 1998, as Steve Waugh stared into his bowl of ice cream at tea during the first final of the Carlton & United series at the MCG and told Tom Moody to stand down as Australia's ODI opener because he wanted Adam Gilchrist to go in first? Or on November 7, 1999, when Gilchrist walked to the wicket as Australia's Test match No. 7 and made 81 from 88 deliveries? Or maybe it was earlier, much earlier, in 1994, when he moved from New South Wales to Western Australia because he couldn't shake Phil Emery from his native State side?

Or perhaps it was when he made 149 not out to win the game against Pakistan at Bellerive in his second Test; or the double-hundred against South Africa, when he was in such exquisite form that he amused himself by trying to hit a sponsor's billboard offering a million dollars; or when Mike Atherton looked across at Duncan Fletcher's notes on the tactics for bowling at Australia in 2001 and saw that all Fletch had written next to Gilchrist's name was "?".

No, the world really changed once the rest caught on and "the Gilchrist role" became a thing, despite the fact that there was only one Gilchrist. It's hard to think of another modern cricketer with such a singular individual influence on the game. A specialist position had its job description rewritten, its specialisation changed overnight. Once, it had been nice to have a wicketkeeper who could bat. Now, not only did a wicketkeeper have to bat, he had to average 40; he had to open against the white ball and smash it over or through the field. It was a reality shift, a future shock, and along came the fruits of its influence - England alone have produced in recent years Geraint Jones, Matt Prior, Craig Kieswetter, Steven Davies, Jos Buttler, Sam Billings, Jonny Bairstow and more, a pattern repeated across the world.

The question now is: "For how much longer?"

That Test cricket will soon feel the shiver that has run up through T20 to ODIs is beyond doubt. What we don't know is how change will manifest itself.

My thought is that the Test game will become more about phases of play, about specialisation, when the small advantages and momentum shifts are identified.

To best affect the game, batting orders may become more fluid. The period before a second new ball, for example, could be targeted for maximum effect. There's no point having your Gilly sitting in the shed waiting for his turn then.

Tiring bowlers, hot weather, excessive seam movement, an approaching session break - there are very many small events in games that are not always matched by having the right man in at the right time.

"My thought is that the Test game will become more about phases of play, about specialisation, when the small advantages and momentum shifts are identified"

Bowling attacks have never been thought of as rigidly as batting orders. A captain's job is to get the right bowler on at the right end at the right time. This is the thinking that could extend into batting.

It's not a tactic in itself, more a manifestation of the need to react more quickly to a long game, to seize a moment, to express fully how you want to play.

The concentration of skills that has maximised limited opportunity in white-ball cricket will inevitably slide upwards, and the notion of a very fixed role outside of opening the batting will slide with it.

There is a physical and emotional intensity to the role of batsman-keeper that is limiting too. Gilchrist's Test career lasted eight years. Matt Prior has retired at the age of 31. Kumar Sangakkara, Brendon McCullum and AB de Villiers have given the gloves away. It asks too much of a batsman to concentrate so intensely for every moment that they are on the field, season upon season, year upon year.

Gilchrist first shook the game and then changed it. It's unrealistic to expect the role he embodied to remain constant in an environment of flux. The jobs that he united so fully may soon split apart once more.