"Tickets for the cricket. Anyone want tickets for the cricket?"

Outside the Oval tube station, touts flogging tickets to the game are ubiquitous. An hour before play, it is grey, gloomy and drizzling, rendering a delayed start inevitable. And yet the touts are kept busy; more than 20,000 tickets were sold in advance for each of the opening three days.

The Oval Test, traditionally the last of the English summer and almost always commencing on a Thursday, has been a ritual for many years. A few weeks before the game, local buses are emblazoned with adverts for "The Final Test". Many in the crowd have been going to the Test for years, and regard it as part of the essence of summer.

If the abiding sense here is of continuity, not change, around the world it is very different. Test cricket, a game that has enthralled spectators for 139 years, is on the cusp of a series of profound changes. When the next decade begins, it seems certain that tickets for The Oval will still be sought after, but those coming might be watching a very different game.

The big picture

In the mid-1980s, the Victorian Football League (VFL), Australia's primary Aussie Rules competition, was in disarray off the field. Attendances were plummeting, clubs were languishing in debt, and administrators seemed incapable of transcending parochialism. Yet, after years of stasis, the VFL recognised it had to act urgently, and emerged stronger than ever as the rebranded Australian Football League, with a broader reach and more teams. The transformation of the sport, and a book detailing it, The Phoenix Rises, have been studied by senior figures in the ICC. Over the last year - driven by the dwindling commercial rights for Tests, concerns about an absence of context in international cricket, a lack of opportunities for Associate nations, and the fear of T20 leagues cannibalising the international game - they planned a comprehensive reinvention of the sport.

Longer sessions in four-day Tests could prompt the selection of two wicketkeepers, especially for matches played in stifling heat

The ICC's favoured solution was to introduce two divisions in Test cricket from 2019 - seven teams in Division One, five in Division Two - with promotion and relegation every two years, replacing what James Sutherland, the CEO of Cricket Australia, terms "a hotchpotch of bilateral events that lack structure and context". In Dubai this September, the plans were abandoned, following opposition from India, Bangladesh, Sri Lanka and Zimbabwe.

The ICC still believes in the three principles behind the idea for a restructure. First, a trophy cycle should take no more than two years. Second, more teams should be playing Tests. And third, there should be a small reduction in how many Tests each country plays: less Test cricket but better Test cricket, giving each match a sense of occasion and reducing club-versus-country clashes. These points will influence what Test cricket looks like in 2020.

"We are still working hard at getting in place some form of structured league that will be in place by then. There's not much favour for a two-tier Test system but an alternative to that would still be good," says David Richardson, the ICC chief executive.

The structure the ICC now favours is for 12 competing nations - the ten current Test teams, plus Afghanistan and Ireland - to make up two groups of six. Teams would play a series against every nation in their conference, as well as some matches against teams from the other. Matches within this structure would count towards a league table, and at the end of a two-year period, the leading team from each conference would face the other in a playoff final.

Although this system would be less easy to understand than a simple two-division model, leagues with asymmetrical fixture lists exist in other sports, such as the National Football League (NFL) and Super Rugby, the southern hemisphere's club rugby competition. Should the conference system be scuppered, the ICC hopes to reach agreement on a more modest scheduling reform: mandating that all 12 Test nations play each other over a six-year cycle, but in as little as one Test either home or away. Even a solitary guaranteed Test every six years against Australia, England and India would be commercially significant for the poorest nations.

A pooled broadcast deal for overseas rights would help reduce cricket boards' dependency on tours by India, and make it easier for fans to watch neutral series © IDI/Getty Images

Whether or not the new Test league is agreed, there is likely to be a playoff every two years, played possibly over six days to increase chances of delivering an outright winner. It is planned that the inaugural playoff to determine the world Test champion will take place at Lord's in 2019. "The idea is to create a real buzz around the event for a week, like the Champions League final, holding it in a place where you are guaranteed interest in Test cricket - like Lord's, Sydney, or Kolkata," Richardson says. "It becomes almost a life-changing experience for the players who make it to the final."

Within the ICC it is felt that the playoff, even if not accompanied by the broader reform it hopes for, is considerably better than doing nothing. It would give Test cricket a pinnacle event and qualification for it would add context to other Tests. A senior broadcasting insider from India and Rohan Sajdeh, a senior partner at the Boston Consulting Group who was the architect of a previous plan to restructure Test cricket in 2008, both believe that, while an improvement, a solitary playoff is not ambitious enough. A longer event between, say, four teams would attract greater interest and commercial value, but the international calendar makes such an event every two years difficult to schedule.

While many Associates were dismayed by the collapse of the two-divisions plan, the ICC still intends to allow two new countries into Test cricket. This in itself constitutes a radical step. It would increase the number of Test nations by 20%, and would be the first time since the 1920s that more than one new Test country has been added in the same decade.

It is envisaged that Test status will be decoupled from Full Membership, so the new Test nations will not necessarily become Full Members of the ICC. The ICC plans to grant indefinite Test status to two countries, probably from 2019. It is understood that the criteria used to determine the two new sides will not just be performance in the latest Intercontinental Cup but performances over the last three editions, and the quality of their domestic set-ups. In practice, this virtually guarantees that Ireland and Afghanistan - currently ranked first and second in the Intercontinental Cup, in any case - will be the two new Test nations.

"We could have spinners bowling so the ball will get to batsmen just as it's about to reach the second bounce"

As well as their performances on the field, the ICC has been impressed with the cricketing structures in both those countries. Ireland's three-day domestic competition has just been awarded first-class status from 2017. Afghanistan have had a four-day domestic competition since 2014, and have applied to the ICC for the competition to gain first-class status; it could be granted as early as next February.

Two new Test nations could be the beginning of the expansion, not the end. "There's no reason why we shouldn't have more and more countries playing Test cricket," says Richardson. The ICC is particularly struck by Nepal's potential and fan base. Under discussion is a playoff between the winner of the Intercontinental Cup and the 12th-ranked Test nation, so the number of Test teams could gradually increase. The playoff would in effect be a promotion-relegation mechanism into the top 12 that, the ICC hopes, will take place every two years with no team exempted.

More immediately, the ICC will have to grapple with how to integrate the two new Test countries. It believes that a sensibly designed fixture list could help Ireland and Afghanistan be more competitive in their early Tests than Bangladesh were after their elevation in 2000. This was one reason why the ICC favoured a two-tier Test system. The conference system is now seen as the best way, partly because of the clear risk that, without such a structure, Ireland and Afghanistan would suffer from a dearth of fixtures. Zimbabwe, after all, played only two Test matches between November 2014 and October 2016.

And yet serious questions remain, most fundamentally of funding. Ireland have sometimes had to cancel planned ODIs against Test nations because of a lack of funds; funding is easier for Afghanistan, partly because of support of foreign governments, including Germany and the USA.

Without fundamental reform of cricket's calendar and finances, warns Tony Irish, executive chairman of the Federation of International Cricketers' Associations (FICA), there will be a rise in free agency and premature retirements from Tests. The wage gap between domestic T20 leagues and Test matches has widened - in their new report, FICA found that a leading cricketer could earn US$230,000 a year playing in all three formats of the game for New Zealand, but $500,000 for playing in three domestic T20 leagues. It has already contributed to players retiring prematurely from Tests, including a coterie of West Indies players and Brendon McCullum.

Orange isn't the new pink: while there have been concerns about feasibility, pink is likely to remain the colour of choice for day-night Tests © AFP

In a FICA survey, 58.6% of players from Bangladesh, New Zealand, South Africa, Sri Lanka and West Indies said they would consider rejecting a national contract if they were paid significantly more to play just domestic T20 leagues. There will be ever more opportunities for them to do so, with South Africa preparing to launch a new T20 Premier League, and the PCB declaring that within five years the Pakistan Super League (PSL) "will be the most exciting event of the year, far more exciting than any FTP [engagement] could ever be".

T20 money is particularly alluring for players from poorer Test countries - an international player for Australia or England earns four times as much as one from Sri Lanka, New Zealand or West Indies. "We need some sort of financial remodelling to ensure that smaller countries can pay their players adequately to play Test cricket," Irish says. Test cricket has long ignored the lessons of the relatively egalitarian distribution of funds in competitions like the NFL and the English Premier League.

Now Test cricket's very lack of competitiveness is putting broadcasters off the sport. Consider the Australia-West Indies Test series a year ago. Six West Indies cricketers, including five former Test players, were playing in the Big Bash League, and West Indies were predictably thrashed by Australia in the Tests. Crowds for the Boxing Day Test were the lowest for 21 years. Channel Nine later blamed the poor quality of cricket in the summer, and the Tests that finished before the fifth day, for a decline in revenue and a drop of over 20% in its share price. Some Tests today lose hosting boards around $500,000. According to Richardson, "If teams are playing in a proper structured competition, the value of bilateral series will increase and improve, at least enabling countries who want to play Test cricket to break even."

A possible source of funding is an initiative by several boards to pool their overseas broadcasting rights (that is, the rights to their home matches in overseas markets) and sell them collectively. At its core, the plans to pool broadcasting rights are about enabling countries to reduce their financial dependence on bilateral tours from India, and building a new alliance in the post-Big Three landscape - principally between Australia, England, New Zealand and South Africa. A system of pooled TV rights is likely to lead to more rights money, and it could also have some meaning for fans: it would be easier to watch Tests involving other nations because overseas broadcasters would have to buy rights for a package of matches, not merely those hosted by one country.

The four-day idea has been championed since 2003 by Andrew Wildblood. "Don't be scared to fail. We're going to die wondering if we don't do something soon"

The ICC is also reviewing the game's financial distribution model. By next June, at the latest, it is hoped that member nations will agree to substantively revise the financial reforms of 2014, which awarded more ICC revenue to Australia, England and India than to the other 102 members combined.

Otherwise, the ICC's plan to increase competitiveness in Test cricket centres, ironically, on the World T20. It is likely that the World T20 will continue to take place every two years rather than four, as the plan had been. This would raise about $300 million in the 2015-23 rights cycle. Cash raised from the World T20 will be used for a Cricket Fund worth about $40 million a year, which will help pay for matches - Tests, and also some ODIs - deemed economically unviable, and to pay cricketers from the poorer countries (the proposed fund is different from, and bigger than, the existing Test Cricket Fund). The Cricket Fund should not be understood as an act of altruism; rather, it is one of pragmatic self-interest. In the small world of Test cricket, it is in all countries' interests for their opponents to be competitive.

The playing conditions

Administrators will not merely affect the structure in which games take place. They will affect the nature of the games themselves.

Unwittingly, day-night Tests have served as a case study for the conservatism of cricket administrators. The ICC approved playing conditions for day-night Tests in 2012, yet it took a further three years for the inaugural day-night Test, and another year for the second. But support for the concept is becoming more widespread: Pakistan just played a day-night Test, in the UAE, for the first time, Australia will play two day-night Tests this summer, and England will play their inaugural day-night Test next August. By 2020, Sutherland believes that the majority of Tests will be day-night. Should day-night Tests become common, they will bring with them new conventions, like twilight tickets for the final two sessions, to attract working fans.

The timings make day-night Tests easier to watch on TV too. They "could be a part of the solution" to making Tests more commercially attractive, believes the senior broadcasting insider from India. Based on ODI figures, he reckons that day-night Tests could be watched by 25-30% more people than day ones.

The ICC's plan is to use the World T20, which will continue to be played every two years, to finance the less viable Test format © IDI/Getty Images

By 2020 we are very likely to see the rebirth of four-day Tests. The rationale for them is simple. The matches would free up days to accommodate more three-Test series. They could be played from Thursday to Sunday, as is the norm in golf tournaments, so the final day would take place when most people could watch. The idea has been championed since 2003 by Andrew Wildblood, a former senior international vice-president for International Management Group. "If you want to do something about Test cricket then do something," he says. "Don't be scared to fail. We're going to die wondering if we don't do something soon."

The ICC is exploring the idea. It would need to rewrite the playing conditions, and the move would need to be accompanied by further improvements in drainage facilities and floodlights. Anurag Thakur, president of the BCCI, opposes the plans for four-day Tests, while Pakistan are understood to have concerns that it would be hard to fit in 100 overs a day in the UAE. Yet there is sizeable support, with board members from Australia, England, New Zealand, South Africa and Sri Lanka among those in favour. Over the next two years the ICC hopes to trial the concept of four-day Test matches and then assess the success of the experiment. The ICC would like all matches in any new structure, from 2019, to be played over the same conditions.

By 2020 it is likely there will be an acceleration in the trend of staging Tests on boutique grounds. The strategy was pioneered by New Zealand, whose chief executive, David White, last year addressed the ICC about the emphasis on selling out smaller venues - thereby driving demand, and creating the best possible spectacle for TV - rather than playing in larger stadiums that can never be sold out. Such thinking can also be seen in India's current home season, in which as many as six venues, including Dharamsala and Ranchi, host a Test for the first time. The crowds for Indore's debut Test, against New Zealand in October, were excellent.

Sutherland believes that the majority of Tests will be day-night by 2020. They will bring with them new conventions, like twilight tickets

According to Benedict Bermange, the Sky Sports cricket statistician, over rates in Test matches have fallen from 18.84 in the 1950s to 14.00 in the 2010s. In August, the England opener Alex Hales gave a fan a partial refund on his ticket after the fan moaned about a day in which only 81 overs were bowled. The ICC hopes to make such grumbling less routine, and is considering ramping up penalties for captains, making suspensions more common and allowing umpires to impose penalty runs during a day's play for slow over-rates. If four-day Tests of 100 overs per day are introduced, then greater vigilance on over rates is essential. Dividing the days into two long sessions, of 50 overs apiece, could be another way of freeing up time.

Home advantage is an issue of concern for administrators as well as broadcasters. "If fans know that the home team is always going to win, which has been happening for the past five years, it will lead to disengagement," says the Indian broadcasting insider. In limited-overs cricket, home advantage is less stark, giving those formats the benefit of greater unpredictability. The ICC believes that the trial in English county cricket this year, of giving visiting captains the chance to bowl first without a toss, has been successful; the ICC Cricket Committee will discuss the concept next year. To mitigate home advantage, the ICC would like to monitor pitches more closely. It is hoped that reducing the volume of Test cricket - in England, for instance, it is likely that from 2020 the number of Tests per summer will be cut from seven to six - and ensuring that matches count towards a league table, will cause teams to take tour preparations more seriously.

The cherished concept of a Test match as a contest between two 11-man teams might also be revised. CA has adopted concussion substitutes in all domestic competitions, except the Sheffield Shield (because it was not cleared by the ICC Cricket Committee), and supports their introduction in Test cricket. As well as for concussions, Sutherland advocates "further debating the merits of injury substitutions - and perhaps, to be even more provocative, tactical substitutions". Such an idea could help to keep pace bowlers in the game for longer, as one-innings specialists - and, according to Trent Woodhill, a leading T20 coach, make it a better spectacle.

Are bat sizes going to go out of hand over the next few years? © AFP

"Imagine Lord's on a Sunday afternoon, England are five for 220 chasing 290 and there's an announcement that [Lasith] Malinga is coming on as a replacement." It is a seductive notion, but there is little appetite within the ICC for such a radical shift. "I'm hesitant to tinker with the laws of cricket," Richardson says about substitutes. "Concussion occurs so infrequently it's probably not an issue."

Technology

Cricket Australia is on the verge of an agreement to live-stream international cricket on Qantas flights. This is far less ambitious than the streaming pioneered by Major League Baseball (MLB), where, through the company Major League Baseball Advanced Media, fans can watch live streams or broadcasts of any MLB match. Yet they hint at the innovative broadcasting deals that the coming years could bring.

The use of new technology in umpiring will be determined in large part by the BCCI's stance on the DRS. "I think the future will pretty much depend on the next six months and what the BCCI decide to do with DRS," says Warren Brennan, the inventor of Hot Spot. "If they support it then there may be some impetus for developers to continue to do R&D to produce new technology for cricket." Without the DRS being consistently applied in all international cricket, "new investment in cricket technology is probably unlikely". But the BCCI's approach to the DRS is changing: it agreed to use the system for the winter's Test series against England on a "trial basis".

Dilip Jajodia of Dukes is "a great believer in fluorescent orange" because it is the clearest ball to see, across daylight hours, twilight and night-time

Ultimately the ICC would like to take greater control of the use of technology, agreeing to a minimum framework used in every Test match and releasing the necessary funds to pay for this. The use of technology remains a hotchpotch, varying from match to match depending on whether India are involved or how much host broadcasters and boards can stump up: when Zimbabwe hosted New Zealand recently, no technology was used at all, save that for run-outs. Alongside this, more specialist training will be given to third umpires to help them reach the correct decision and speed up the process.

By 2020 there will be pronounced changes in the equipment. Improvements in bat technology and an increase in the thickness of bats have, along with stronger batsmen and shrinking perimeters, contributed to more boundaries off the edge. It is likely that rules governing bat sizes will soon be strengthened. In July, the MCC's World Cricket Committee said that in addition to existing rules on the permissible width and length of a bat, the law should be amended to introduce limitations on its edge, depth and weight. It was mooted that the edge be restricted to 35-40mm, and the depth to 60-65mm. Most players already have bats that adhere to these limits, but David Warner, for instance, has one with an edge of around 55mm and a depth of 80mm.

"We feel it's the time to draw a line in the sand," explains John Stephenson, the MCC head of cricket. "We think that batsmen will be using the sort of bats they're using now, we just don't want it to go any further." Others are less convinced new regulations will have any impact on the balance between bat and ball.

"Restricting bat size will have no effect on the game whatsoever," says Chris King, a master bat-maker at Gray-Nicolls. The next phase in development will be less about size than in how imposing bats seem. "A lot of the bat designs I work on are aimed more at the psychological impact of a shape on the player - and even the bowler. A bat like the Nemesis used by Sam Billings was designed to look powerful and aggressive, a statement of intent."

Is there a case for injury substitutes being used in Test cricket? © AFP

More crucial is what happens to the cricket ball, which is in a period of flux. Partly this is because of day-night cricket. For all the investment in the pink ball, not all are convinced that it is the best option, with concerns that the Kookaburra pink ball goes soft too quickly and doesn't offer much swing or seam. The ball was used, too, in India's Duleep Trophy, played under lights in September. The former India opener Abhinav Mukund told ESPNcricinfo that visibility under lights "is a big factor. When it is scuffed up, the colour of the ball goes from pink to greyish. When you apply any natural substance on it, like sweat or saliva, it becomes black-ish." There was also a concern beyond the colour, about the effect of evening dew on bowlers.

Dilip Jajodia, the managing director at Dukes, is "a great believer in fluorescent orange" because it is the clearest ball to see, across daylight hours, twilight and night-time, and has been used successfully in the Northeast Premier League in Durham. Stephenson too is "not completely wedded to pink balls", although he reckons they are improving, and is attracted to a radical option. "You could play Test cricket under lights with a white ball. Then you could be creative about the outfits they wear. I don't think you should use all-singing and all-dancing coloured clothing, but you could create some nice clothing to give the contrast to a white ball." Nevertheless, it seems likely that by 2020 the pink will be the standard one used in day-night Tests.

Steps could be taken to establish better balance between bat and ball, especially to prevent a preponderance of draws if four-day Tests are in currency. The laws of cricket do not specify the materials for a cricket ball. "You can make it with a bigger seam, you can use different materials, you can make it bounce more," says Stephenson.

Within the ICC it is felt that the playoff, even if not accompanied by the broader reform it hopes for, is considerably better than doing nothing

"I can produce a ball that would make a Test over in two days, one that shines forever and has a huge seam," Jajodia says. More realistically, bowlers could gain a little more assistance if balls had a slightly bigger seam, which would create more movement and turn, without fundamentally altering the balance between bat and ball. Dukes is confident that the centre of the ball could be tinkered with to prevent it going soft quickly; the surface could be made shinier to assist swing bowling.

A further thought, one supported by Stephenson, is "to allow the bowlers a bit more latitude when it comes to doing something with the ball, to allow reverse swing". The MCC is undertaking a thorough review of the Laws and is considering giving bowlers more leeway.

One DRS-related change has already been enacted by the ICC. From September 22 this year, not-out lbw decisions could be overturned on review if at least half the ball would have hit the outside of leg or off stump; earlier, they could only be overturned if half the ball was hitting the middle of those stumps. The tweak effectively makes the stumps wider by 1.9 centimetres on either side.

Pitches are another way to redress the balance between bat and ball and help Tests produce a compelling spectacle. Tests are demeaned by wickets that are slow and low and offer scant support to either bowlers or batsmen. In 2010, the ICC introduced regulations allowing match referees to mark a pitch "poor" not just if it offered too much assistance but also if it offered too little, as in the Trent Bridge Test of 2014. Similarly, the ICC issued official warnings to Kingsmead, Durban and Queen's Park Oval, Port-of-Spain after Test matches this August were ruined by poor drainage. By 2020 match referees would have become more vigilant in clamping down on substandard pitches and outfields.

The game itself

In recent years, the continuities in how Test cricket is played have been more striking than the changes. Run rates received a conspicuous boost in the era of Steve Waugh and Adam Gilchrist, but have since stabilised. The same is true of the proportion of matches ending as draws: 24.5% of Tests in the 2000s, and 24.27% in the 2010s (the significant shift happened earlier: 35.73% of Tests in the 1990s ended without a victor). Run rates and the number of sixes per match have actually declined slightly from the 2000s to the 2010s, according to CricViz, the analytics company.

Without significant reform to five-day cricket, we could see more and more cricketers retire early from the international game to play T20 franchise cricket © CPL/Sportsfile

From the data, it is virtually impossible to detect any impact of T20 cricket on Tests. It is the same with other facets of Test cricket: except for matches played in Bangladesh and Sri Lanka the proportion of wickets taken by spin and seam has remained stable. The average length of an innings has barely altered: from an average of 92.47 overs per innings in the 1970s down to 88.62 in the 2010s, according to CricViz. So the essence of the game has remained fundamentally unchanged since the early 2000s, and, with the exception of an increase in run rates of about 0.50 an over, all the way back to the 1970s.

Predictions of dramatic shifts in how Test cricket is played, therefore, come with a caveat. For all the shifts in Test cricket now being discussed, the game has been through a swathe of innovations in the past 50 years - the invention of helmets; more imposing bats; stronger batsmen; the proliferation of reverse swing and then the doosra; the standardisation of five-day Tests; the end of the rest day; the introduction of the DRS - and yet retained its underlying character. Yet the coming years could herald a series of subtle but significant changes in the game.

Although batting against a red ball is a profoundly different challenge to batting against a white one, as exemplified by Hales scoring at a slower rate than Alastair Cook this summer, run rates in Tests are likely to increase again. On good pitches, New Zealand coach Mike Hesson believes, rates are already rising. "Unfortunately you've also got some games where the pitch is slow, the outfield is incredibly slow, and you're scoring at two an over. That brings the average back." Andy Flower, England's former coach, who is now in charge of England Lions, expects rates to increase "because players have more confidence". A shift to four days would be likely to drive run rates higher still; even in five-day Tests, New Zealand's approach to batting is driven by Hesson's belief that "we need eight sessions to take 20 wickets, so we need to score our runs in seven".

While Test runs might be scored a little faster in 2020, another question is whether more runs will be scored. The average number of runs per wicket in Test cricket rose from 31.64 in the 1990s to around 34 in the 2000s and 2010s, meaning a team will score an average of about 50 more runs over two innings. While Hesson says that this trend is "a little bit cyclical", and could be challenged by a fine young crop of pace bowlers, such as Kagiso Rabada, Mohammad Amir and Mitchell Starc, he also thinks something greater is at work. "Bowlers have probably gone almost as far as they can within the legal limits," he says. "The way that batsmen can score 360 degrees around the ground is amazing really. I don't think bowlers can compete with that unless the pitches offer them a little bit more."

Most countries will play fewer Tests in 2020 but if those mean more and are treated with more reverence, it might make Test cricket stronger

Bowlers have fought back before: through the googly, Bodyline, reverse swing and the doosra. They could do so again. "Bowlers need to get creative," says Jason Gillespie, the former Australia fast bowler and Yorkshire coach - though, he adds, they are handicapped by an arduous schedule that limits opportunities to develop new techniques.

The Under-19 World Cup this year provided a glimpse of a bowling innovation that could shift the parameters of the game. Kamindu Mendis, Sri Lanka's spinner, bowled ambidextrously, alternating between left- and right-arm bowling depending on who was batting, so he could always turn the ball away from the bat. Recently Yasir Jan, a young ambidextrous fast bowler discovered at a talent hunt in Pakistan, was signed up by the PSL team Lahore Qalandars on a ten-year developmental contract. Gillespie reckons that there could be more of the kind. "If they've started young enough, and developed their skills over a period of time then why not?"

It might not be the only radical change in bowling in the coming years. While Gillespie still considers Test cricket "the war of attrition" defined by whether the batsman or bowler can own the area six to eight feet in front of the batsman just outside off stump, bowlers of all types will use more variations. They will bowl from a range of trajectories and use wide-arm deliveries. Gillespie believes the scope for innovation is biggest for spinners. "We could have spinners bowling so the ball will get to batsmen just as it's about to reach the second bounce: it's still a legal delivery but that could make it a lot harder for batsmen to play. What's stopping a fingerspinner walking in to bowl and then dropping on their back knee and bowling from a very low trajectory? Could that be brought into the game?"

Could there be bigger totals in Tests in four years? Have bowlers exhausted all the ways to keep batsmen in check? © Getty Images

The proliferation of day-night Tests could be a boon to bowlers, because of the difficulty in seeing the ball in twilight, as was the case in the inaugural day-night Test in Adelaide last year. "It's like batting in cloud cover," says Stephenson. "Suddenly the cloud comes over, it zips all over the place." Having seen day-night cricket for seven years in the MCC v champion county match in Abu Dhabi, Stephenson believes that the twilight period can also benefit the batting side if there are two set batsmen facing a slightly older pink ball.

By 2020, the captain's tendency to bat on winning the toss could become less pronounced. "In certain parts of the world, pitches don't deteriorate so you end up wanting to bowl first so that you can bat last: in Australia, New Zealand and England to a lesser degree," Hesson explains. So far, though, there has been only a minuscule increase in the number of teams choosing to bowl - from 34.06% in the 2000s to 35.15% in the 2010s, according to CricViz, though this statistic cannot measure whether more captains are choosing to bowl first because they want to bat last rather than exploit the assistance for bowlers on the first morning. Four-day Tests promise to accelerate the trend of sides choosing to bat second: there will be less time for pitches to deteriorate or, for weaker sides, less time for them to bat out for a draw.

If the number of overs increases to 100 overs per day, possibly bowled over two sessions rather than three, it will require even more of bowlers. The notion of a four-man attack in Test cricket is already imperilled. "You need five in the modern game, especially with the amount of cricket that's being played," Hesson says. Four-day Tests could make allrounders essential. These have always been strikingly rare - indeed, Aubrey Faulkner remains the only Test allrounder in history to average more than 40 with the bat and under 30 with the ball - but necessity will force teams to fast-track cricketers with all-round potential, as in the case of Mitchell Santner, who had a bowling average of over 50 in first-class cricket when he made his Test debut for New Zealand. Sides will try and manufacture allrounders out of batsmen who can bowl, as in England's use of Moeen Ali, a No. 3 and often a second spinner in county cricket.

While many Associates were dismayed by the collapse of the two-divisions plan, the ICC still intends to allow two new countries into Test cricket from 2019

Longer sessions in four-day Tests could prompt the selection of two wicketkeepers, especially for matches played in stifling heat. The increased batting aptitude of wicketkeepers means that many countries already have two close to selection as batsmen alone; rotating the gloves between sessions could be a way of ensuring they maintain focus. "Most sides do have the option of doing that," Hesson says. "We do with Luke Ronchi and BJ Watling, they're capable of playing in the same side. In extreme heat it's a real option." As superior statistical analysis comes in, the role of the modern keeper-batsman could be re-evaluated, with more emphasis on the keeping. "If you don't have someone who averages over 40," says Nathan Leamon, the England performance analyst and founder of CricViz, "then you've got to weigh the difference between a keeper who bats and a batsman who keeps. Generally the cost of the chances missed is harder to quantify, and may well be underestimated."

Leamon says that "there is evidence to suggest that currently the biggest headroom, in terms of possible improvements in the game, is not in batting or bowling, but in fielding". Ambidextrous fielders will become more common and, accompanied by better data, fielding will be more critical in selection. In turn, this could make scoring trickier for batsmen whose games are built on quick singles and working the ball into gaps.

With a rationalised schedule, more players might be able to commit to playing in all three formats for longer. "I don't think you'll be able to survive just as a Test match cricketer," says Hesson, who envisaged a far greater degree of specialisation a few years ago. In turn, this will mean that Test batsmen and bowlers are more influenced by trends in limited-overs cricket. Hesson used to think, too, that coaching would become more specialised, but no longer.

What sorts of alterations can we expect the MCC to allow the bowling sides to make to the cricket ball? © Getty Images

"The value of team culture is too important and the success of the team is based around that. If you're bringing in different coaches to coach different forms of the game, you're going to have different cultures and subconsciously or consciously you are going to develop two or three distinct cultures, and players are going to prefer one over the other." It is more likely, Hesson believes, that coaches will take occasional tours off rather then step aside from one form completely.

In conclusion

In 1875, William Rathbone Greg, an English essayist, wrote that people were living "without leisure and without pause - a life of haste". This did not sound like an opportune moment to introduce a new sport in which a game would normally take five days. That Test cricket has survived all this time is testament to its richness.

The accepted narrative of Test cricket in irrevocable decline does not quite hold up. Data on crowds - admittedly very shoddy in many countries - tells a different story. Look at grainy footage of classic Test matches, even the most mythologised games of all, like Headingley 1981, and there are a striking number of empty seats. "Nothing is more responsible for the good old days than a bad memory," the American columnist Franklin Pierce Adams said.

The accepted narrative of Test cricket in irrevocable decline does not quite hold up. Data on crowds tells a different story

This is not to ignore the challenges that Tests do face. Viewing figures for India's Tests with South Africa last year, a series that had context in spades, were particularly disappointing. They highlighted the sense of Tests being in competition with other formats - the big difference with the past. Generally, TV viewing figures have not declined much for Test cricket, but the difference in figures between Tests and the two limited-overs forms has increased, which is the salient point. Between 2012 and 2015 in India, the average viewer figures were 30-40 million per day in Test cricket, 120-130 million in ODI cricket, and 140-150 million in T20I cricket (where matches are typically played at prime time, and fetch higher advertising rates).

The source for these figures is the senior Indian broadcasting insider. I put it to him that if cricket is just looking to maximise its revenue, there would never be another Test match in India - or, indeed, perhaps any outside the Ashes. He agrees. "One of the big questions that cricket needs to ask itself is: are these three formats or three different sports themselves? What is it that a Test stands for that is different to a T20 or ODI? Why should a 15-year-old boy watch a Test over a T20 or ODI?"

And yet, for all these profound concerns, he says, "There's plenty of examples of brands reinventing themselves to cater for a new audience, and Tests need to." Compared to T20 cricket, Tests have barely been marketed at all. "The ebbs and flows are truly unique to Test cricket. Cricket's ecosystem needs to find a way of communicating that and then heightening it."

Sunset boulevard: a nocturnal future beckons for Test cricket © Getty Images

In 2020, Test cricket will be a faster game, played on pitches that are more conducive to exciting cricket. There will be two new teams, more context to the matches, with a playoff every two years. More matches will be played when people can watch them: day-night Tests will be frequent, and apart from traditional games like the Lord's Test and the Boxing Day and the New Year's Tests in Australia, might even become the norm; four-day Tests, played from Thursday through Sunday, could become standard too.

With sagacious, enlightened administration - admittedly, hardly conspicuous in cricket's history - players might be less compelled to choose between different formats of the sport. Most countries will play fewer Tests in 2020 but if those mean more and are treated with more reverence it might make Test cricket stronger. In a fractured and uncertain world, the very ways in which Test cricket can feel out of sync - the length of the matches, the traditions of the game - might come to be seen as strengths. Consider how the physical book, a few years ago considered to be obsolete, is now resurgent: rather than being submerged by modernity, it is treasured as a refuge from it. Test cricket will have to struggle to make itself more relevant - it has always had to.

At the start of the next decade, then, people will still be talking about the viability of Test cricket. They probably always will.

Tim Wigmore is a freelance journalist and author of Second XI: Cricket in its Outposts

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