A forecast that is usefully good all the way up until it is catastrophically wrong.

In decision-making, the ability to forecast, from given facts and past experience, is a critical capability but one fraught with issues. An example I use to illustrate the danger of extrapolating into the future from accurate past data is that of the Turkey. From their perspective, all available evidence supports the proposition that humans are their very best friends. Humans provide shelter, bring food, protect the Turkey from such dangers as foxes. For the entirety of their lives, all data supports the Turkey in its belief in the friendship of humans. And that interpretation and forecast is good all the way up to the day before Thanksgiving at which point it becomes catastrophically wrong.

I came across this letter from E.B. White to his publisher providing some background on how he came about writing his classic, Charlotte's Web (A Book is a Sneeze by Shaun Usher). In it, White describes the awkward circumstance of a farm.

A farm is a peculiar problem for a man who likes animals, because the fate of most livestock is that they are murdered by their benefactors. The creatures may live serenely but they end violently, and the odor of doom hangs about them always. I have kept several pigs, starting them in spring as weanlings and carrying trays to them all through summer and fall. The relationship bothered me. Day by day I became better acquainted with my pig, and he with me, and the fact that the whole adventure pointed toward an eventual piece of double-dealing on my part lent an eerie quality to the thing. I do not like to betray a person or a creature, and I tend to agree with Mr. E.M. Forster that in these times the duty of a man, above all else, is to be reliable. It used to be clear to me, slopping a pig, that as far as the pig was concerned I could not be counted on, and this, as I say, troubled me. Anyway, the theme of "Charlotte's Web" is that a pig shall be saved, and I have an idea that somewhere deep inside me there was a wish to that effect.