The footmarks are a spinner's inheritance and most of them waste it

Bowling into the rough sounds simple until you notice how few deliveries actually land in a patch the size of a doormat.

By day four there is a patch of broken surface outside the left hander's off stump roughly the size of a doormat, created entirely by fast bowlers following through where they should not. It is the best thing that will happen to the spinner all match, and I would guess he lands fewer than one ball in four in it.

The geometry is unforgiving. To hit that patch an off spinner has to bowl from a specific point on the crease at a specific length, and the length that puts the ball in the rough is usually fuller than the one he has been bowling for three days. Miss short and the ball lands on good surface and does nothing. Miss full and it lands past the rough on the batter's half volley. The target is smaller than the margin most spinners operate with, which is why the ones who exploit it well look like a different category of bowler.

There is a related mistake that gets made constantly. A ball that pitches in the rough does not necessarily turn more, it turns unpredictably, and that difference matters for how you set the field. Bowlers who expect big turn set a leg side field and then watch a ball skid straight on past the outside edge with nobody at slip. The rough produces variance, not direction, and the field should be set for the ball that does nothing as much as for the one that spits.

The batter has answers, which are also worth stating. Use the crease, get outside the line and play with the pad, or come down the pitch and take the pitch of the ball away before the surface can do anything. That last one is the most reliable and the least used, because it requires a batter to advance against a spinner in the fourth innings, which is uncomfortable and looks reckless when it goes wrong.

What irritates me is how rarely a captain protects the rough on his own side. Fast bowlers running through the danger area get a warning from the umpire, eventually, but nobody instructs them to keep off the patch their spinner will need on Sunday. It is treated as the umpire's problem. It should be a team decision made on Thursday morning.