A drop-in pitch never quite grows its own roots

Trays of turf grown elsewhere solve a scheduling problem for stadium owners and create a subtler one underneath the surface.

A drop in pitch is grown in a nursery, in a steel tray, and craned into a hole in the middle of a stadium a few days before play. It exists because modern venues host football, concerts and cricket in the same month and a permanent square cannot survive that. As an engineering answer to a commercial problem it is neat. As a cricket surface it has a specific weakness that comes from the tray itself.

Grass in the ground sends roots down into a soil profile that continues indefinitely below it. Water drains away, roots follow the moisture, and the whole column binds together over years. Grass in a tray has a floor. The roots reach it and stop, and the profile is however deep the tray is, which is typically much shallower than a prepared square.

That shallowness changes the behaviour of the surface under load. The bounce tends to be even and reliable early, which is why drop in pitches often produce very good batting on day one, and it tends to change abruptly rather than gradually once the top layer starts to break, because there is less depth beneath it to absorb the punishment. You get a flat surface and then, quite quickly, a variable one.

There is also a moisture problem. A tray drains differently from the ground around it and the boundary between the two is a real seam in the earth, which is why fielders sometimes describe a noticeable step at the edge of a drop in block.

None of this makes them bad, and the good ones are genuinely good. Preparation has improved a lot, trays are deeper than they once were, and curators have learned that a drop in needs more rolling and earlier than a permanent square.

What I object to is the pretence that the surface is neutral. A venue that installs drop in pitches has made a choice about what kind of cricket it will host, in the same way that a venue with a short square boundary has, and it should be discussed in those terms rather than as a piece of stadium plumbing.

Ask a curator about a drop in and watch how carefully he talks about the first two days. He knows exactly where the pitch stops being his.