If you were to bioengineer a cricketer in a laboratory, which attributes would you give them? You would make them tall, with long limbs and a whiplash action to extract steep bounce. Add speed, movement both ways and a left arm to offer a point of difference. With the bat, make sure they can whack sixes but also go down the gears when an innings starts to unravel. For an added trait, have them catch meteorites in the outfield and the cordon.

You might end up with Marco Jansen. At the start of the third Test, the 6ft 8in South African had taken 99 Test wickets at 20.81. His 85 against Australia at Gqeberha in the second Test came after South Africa had slumped to 110 for six before his counterattack helped turn a precarious position into an innings victory. Jansen is still developing as a batter, but his 25.66 average before this current Test understates his potential.

Jansen belongs to a great South African tradition. The country’s finest sides have often been built around players who can do more than one job. Mike Procter, Shaun Pollock, Lance Klusener and Jacques Kallis, who scored 13,289 Test runs and took 292 wickets, came to embody the quintessential South African cricketer. That heritage continues in Jansen and Wiaan Mulder, whose wobble-seam bowling comes with the capacity to make 367 not out.

But what makes someone an all-rounder? A recent essay by the analyst Jarrod Kimber argues that “a true all-rounder is not just their numbers, it is the effect they have on the entire team”. The tidy statistical definition, in which a player’s batting average exceeds their bowling average, is inadequate. By that measure Joe Root and Don Bradman qualify. The more useful question is whether a player could be selected for either skill. That separates the all-rounder from the batter who sends down a few overs, or the bowler who can hang around at No 9. More than that, the best all-rounder lets a captain add a bowler without weakening the batting.

A more emphatic measure is a player’s capacity to score a century and take a five-wicket haul in the same Test. It has happened only 41 times, by 29 players. Ian Botham did it five times, more than anyone else. He belonged to a golden quartet alongside Richard Hadlee, Imran Khan and Kapil Dev, who seemed like cheat codes in a sport without substitutes.

England have never quite let go of that romance. Botham, Andrew Flintoff and Ben Stokes embody the free-spirited maverick who can arrive with a cigarette dangling from his mouth and the smell of beer on his lips, then produce a match-winning show. Does that help explain why Sam Curran can seem to receive less love? He is a useful left-arm bowler and inventive batter, but does not fit the same heroic silhouette. England’s idealised all-rounder can cast a long shadow over anyone who does not live up to those standards.

Australia’s problem is stranger. They have produced fine all-rounders, but few who have matched the sustained excellence of Kallis or Garfield Sobers. Keith Miller made 2,958 Test runs at 36.97 and took 170 wickets at 22.97. Alan Davidson, a left-arm fast-medium bowler and accomplished lower-order batter, scored 1,328 runs and took 186 wickets at 20.53. In the first tied Test, against the West Indies in 1960, he became the first player to score over 100 runs and take 10 wickets in the same match.

Since then, Australia have had useful options: Andrew Symonds, Shane Watson, Mitchell Marsh and now Cameron Green and Beau Webster. The issue is not an absence of all-rounders, but the rarity of one who sustains elite contributions in both disciplines. For a country that prizes natural athleticism and power, it is curious how rarely the complete package has clicked.

Perhaps that is because outside Asia we still picture the all-rounder as a fast bowler who can bang it in or seam it off a length. Ravindra Jadeja and Shakib al-Hasan complicate that picture. Both are frontline spinners and serious batters, capable of reshaping a team’s balance. Are they given their due in the west, where a pitch that seams on day one is often treated more kindly than one that offers turn? They are recognised as all-timers, but the language of all-round greatness still favours the pace-bowling showman, which might explain why Moeen Ali felt undervalued for most of his England career.

Wicketkeepers raise a related question. If a keeper bats in the top six, as Adam Gilchrist did on 23 occasions in 96 Tests, are they an all-rounder? They offer two skills, but keeping is a specialist discipline in its own right. Sometimes cricket’s labels are less tidy than its scorecards.

Maybe the most charming all-rounders were the less imposing ones, like New Zealand’s Chris Harris, whose looping “dibbly-dobbly” deliveries and lower-order runs made him useful in a dozen small ways, or Sri Lanka’s parade of batters who could send down darted spin. Perhaps we love all-rounders because batting and bowling are each so difficult that doing both at an elite level feels like the truest measure of a cricketer.

Faf du Plessis recently said he wished Jansen had been in his team when he was captain of South Africa: “He’s two players in one.” Dale Steyn called Jansen “currently the best cricketer in the world”. The laboratory may have produced a unicorn. Now Jansen has to show how many jobs one cricketer can do.