The part beyond the wall

Every slide the widest pile in this garden ever made is in the curve above: 1.57 million of them, on a slope 4,096 columns wide, sorted by how far they ran. The height at a distance is that distance times the share of slides that ran at least that far, and the axis doubles as it goes, which is the drawing that makes area mean what it should: the area under the curve, from the left edge to any wall, is the mean reach a slope that wide would report. The wall is the far end of the slope. Drag it.

Left of the wall is the number a slope that wide gives you. Where a slope was actually built at that width, the table says what it measured, and it is up to a tenth of a column more than the cut, most at the narrow widths, because a real wall does not cut the tail, it pulls it; the note has that table too. Right of the wall is the part of the mean the slope could not show: the reach of every slide that would have run further than the pile is long. Past a thousand columns the data thins out and the curve is the tail’s own law, continued at the exponent the data measured. Choose the literature’s exponent instead and the debt shortens by half a column. That half column is the whole of what nobody knows.

The table is the point. The median does not move at any width; it is a fact about the pile. The ninety-ninth percentile is the wall until the wall passes a hundred and thirty, and then it stops and stays. The mean and the share carried by the biggest one slide in a hundred move at every width, and they are still moving at the right edge of the drawing, on a slope that would take centuries to fill. Fern for what stayed, russet for what moved: what stayed is about the thing, what moved is about the thing and the box together, and the number on its own never says which.

The right edge is a box too. Beyond a million columns the pile still owes the better part of a column, and the table says how much. This piece runs nothing; every number in it is read off a histogram that a session committed, and the note it belongs to is Some of that number is the box.