A spinner should open the bowling far more often than one does

The new ball grips and bounces better than the old one, which is exactly what a spinner wants and rarely gets.

The convention is so settled that people forget it is a convention. New ball goes to the quicks, spinner comes on around the tenth over when the shine has gone and the batters are set. Ask why and you get the answer that a hard new ball is difficult to grip and skids on. Half true, and the half that is false costs sides matches.

A new ball has a proud, hard seam. A spinner needs exactly that, because the seam is what bites into the pitch and converts revolutions into deviation. As the ball wears and the seam flattens, grip on the surface degrades, which is why a spinner in the thirty-fifth over is working much harder for the same movement. The new ball also bounces more, and bounce is what turns an edge into a catch rather than a soft push into the covers.

The other advantage is psychological and it is bigger. A batter walking out at the start of an innings has a plan for pace. He has looked at the seamers, he has decided where his first scoring shot is coming from, and he is watching for movement in the air. Hand him a wrist spinner in the second over with two fielders out and no reference points, and every one of those preparations is worthless. Sides that do it, usually in the shortest format, get wickets from it consistently, and still treat it as a novelty.

The genuine risk is that it goes badly in public. A spinner opening and going for fifteen looks like a captain being clever, and captains are punished harder for clever failures than for conventional ones. That asymmetry, not the cricket, is what keeps the convention in place.

I would also accept that on a green top with heavy cloud cover it is simply wrong, and nobody should be picking a spinner to open in those conditions to prove a point.

But on a flat, dry surface at eleven in the morning, giving the shiny ball to a seamer who will bowl three overs for eighteen is not orthodoxy. It is habit wearing a blazer.