How long can Australia keep waiting on Marnus Labuschagne?

The case against Marnus Labuschagne rests as much on feel as on figures: the back-foot game has gone, the argument runs, and so has the rhythm that good Test batters carry, while one decent half-century could hide the slide. The scorebook is harsher than the eye. Over the last two years he has averaged 25.56 in men's Tests, against 33.22 for top-seven batters over the same period, and in those 29 innings he has not made a hundred.

How far has Labuschagne's form fallen?

The lack of rhythm shows up in his scoring rate as well as his totals. His strike rate over those two years is 49.9, against 57.3 for top-seven batters. So he is scoring more slowly than the norm while also getting out sooner, and the batter who once made Australia's innings feel metronomic now looks stuck at the crease.

The first Test against South Africa at Kingsmead summed it up. He made 37 in each innings, from 58 balls each time, and Australia won by 214 runs. Both times he got in and was useful, then got out before it counted. Across his last ten Tests his best score is 65, made against England last December.

Is there still a case for keeping him?

Any criticism has to be tempered by what he has been. Our ratings, which weigh his whole Test career, still make him worth about 8 runs a match more than an average Test batter.

Paradoxically, that pedigree is the problem. The rating leans on runs made years ago, so it keeps him looking like a batter well above the average while his recent output sits well below an ordinary top-seven player's.

What should Australia's selectors do?

Australia are in a position to make the call. Our ratings make them the best Test side in the world, with a 77% chance of beating an average side, and they have kept winning through his lean spell, including that first Test at Kingsmead.

The worry about one good score papering over the cracks is fair, because his recent run already holds a couple of half-centuries that came and went without starting a run of form. Australia should pick a batter in form for Newlands and send Labuschagne back to the Sheffield Shield to earn his place, because a long career average should no longer guarantee it.