What 'Line of Duty' and Yahoo have in common

The final episode of Line of Duty and news that Yahoo has been sold again have one thing in common, and that is regression to the mean.

Some people are clearly better at some activities than others. Michelangelo wasn't lucky; he was a genius, ditto for innumerable artists and musicians — although I guess you would say they were lucky to have innate talent. But most of us are average in the long run. And that applies to business too.

Regression to the mean describes how the law of averages means that a run of good luck will come to an end: exceptional performance will be followed by poor performance.