Last month, Adam Voges was asked if statistics for day-night Tests should be kept distinct from other Tests. "I don't think that's the silliest idea, to be honest," Voges said. He was right. The silliest idea, at least of those floated in recent weeks, was James Sutherland's suggestion of beach cricket at the Olympics. But different stats for pink-ball Tests? That runs a close second.

This is not to have a dig at Voges, who is a thoughtful, experienced cricketer, a man whose opinions on the game are always worth hearing. He was thrown the question by a reporter and answered with a gut reaction. And he is not alone in having questions over day-night Test cricket. "Test cricket is all about history and tradition, as far as I'm concerned," Ricky Ponting said recently.

Such sentiments are admirable. They reveal a love of Test cricket and a desire to protect it. But the fact that the Australia-New Zealand matches in Perth and Adelaide will both be called Tests is not a case of comparing apples with oranges, rather judging a Red Delicious against a Pink Lady. And for 138 years, all sorts of different cultivars have made up the format known as Test cricket.

Most cricket fans - indeed most modern cricketers - would probably argue that the red ball is one of the defining features of Test cricket. But then, most would also say the same of its five-day duration. In fact, the length of Test matches has varied wildly over the years. Six-day Tests have been scheduled, and four-day Tests, and three-day Tests. And, of course, Tests without time limit.

The term "timeless Test" is most often applied to the 1939 Durban marathon, when England and South Africa played ten days and called it a draw only because England had to catch their ship home. But timeless Tests were common before World War II. Don Bradman played in 52 Tests and exactly half were timeless. Only in his last series did he finally play Tests scheduled for five days.

Len Hutton's monumental 364 at The Oval in 1938, for 20 years the world-record Test score, was made in a timeless Test. That the match only lasted four days is immaterial; that it was timeless affected the way it was played. England batted first and had no compulsion to declare early, so they batted for 335.2 overs and amassed 903. Hutton faced - wait for it - 847 deliveries!

"The question is how successful it will be, and the answer is not straightforward. More viewers will undoubtedly be watching, but if they see dull cricket will they just switch off again?"

If pink-ball statistics are to be kept separate, then surely the records from timeless Tests must also be expunged. Of course, such a suggestion is facetious. Neither of these things should happen. A pink ball and floodlights would have appeared far-fetched to cricketers of the 1930s, while the idea of a timeless Test these days seems as implausible as Willy Wonka's everlasting gobstopper.

The point is simply this: Test cricket evolves. It reflects its era, and over 138 years that means a lot of changes. In the early decades of Test cricket some bowlers still operated underarm. Take a look at the photo on George Simpson-Hayward's profile page. You'd think he was playing bocce, not cricket. He was one of Test cricket's last "lobsters", taking 23 wickets in five Tests in 1910.

And what about the concept of an over? Six balls is now standard, but four was used in the earliest Tests, then five, then six, then eight. And what of the new ball? Captains can take it after 80 overs, but in the past the time frame has varied - it was 55 overs during Australia's 1948 tour of England - and before that a new ball was generally only taken after the score had reached 200 runs.

Few changes have had greater effect than the move to covered pitches. Imagine playing on a surface that remained uncovered even in the heaviest of rain. That is what faced Test cricketers until well after World War II. It poured rain in 1956 at Old Trafford, where Jim Laker took his 19 wickets on an uncovered pitch. It was, in the words of Australian batsman Colin McDonald, "a mud-heap" after the rain came.

All of these evolutions have changed the way the game is played, either subtly or significantly. So too developments in bat-making technology, the introduction of helmets, boundary ropes, neutral umpires, third umpires, umpire reviews, field restrictions, the 15-degree no-ball rule, front-foot no-balls, bigger stumps, lbw rule changes, the list goes on.

Groundsmen bring on the covers AFP

You could argue that these changes are peripheral to cricket's fundamental battle between bat and ball. Specifically, a red ball that swings, seams and spins. But Test cricket balls are all different anyway. Dukes in England and West Indies, SG in India, Kookaburra elsewhere - these brands have subtle but distinct variations in behaviour, in how and when they swing and how they deteriorate.

It is into this ever-changing landscape that the pink ball will appear at Adelaide Oval this week, another example of Test cricket adapting to its era. The aim is to gain more viewers, at the ground but more especially on television, with the day-night Test to air in prime time in Australia's eastern states. More dollars, yes, but also more eyes fixing their sights on Test cricket.

The question is how successful it will be, and the answer is not straightforward. During Sheffield Shield trials, players have noted that the pink ball goes soft quickly, and stops swinging early, both of which lead to a holding pattern in which runs are scored slowly and few wickets taken. More viewers will undoubtedly be watching, but if they see dull cricket will they just switch off again?

Perhaps a return to the "old" new-ball rules would help, with a new pink ball taken after something like 55 overs. If it was good enough for red balls during the 1948 Invincibles tour, why not now? Anyway, the style of cricket will become clearer after the Adelaide Test, though Australia are already considering another day-night Test next summer, against Pakistan.

But not every Test will be day-night, just as not every Test used to be timeless. It is evolution, not revolution. And while it may turn out there are good reasons not to persist with the pink ball and day-night Tests, tradition is not one of them.