Many managers of law departments would rather hear metrics stated as so-called "natural frequencies." They are most comfortable with "one out of five times we prevail on this motion"-- a way to explain a metric that makes it almost visual, tangible. You can touch the odds on your fingers. Not as real to many managers is the less familiar abstraction of a same metric to a percentage - "20 percent of the time we prevail." Even more discomfiting and alien is "0.2," the decimal expression of the same amount. The percentage and decimal forms are sometimes called "single-event statements," unlike "some number out of another number" and its two actual events. Most people, in other words, have a more visceral, hands-on understanding if a lawyer estimates two chances out of 10 of being sued, rather than either cognitive functions of 20 percent or 0.20.
Evolutionary cognitive psychologists offer an explanation. They believe our brains developed to cope with a savannah that had observable and countable events; if two out of three waterholes were full, it was advantageous and normal for our forebears to favor use of the natural-frequency way of stating that fact. Statistics make more immediate sense when that tactile phrasing is used. Mathematical fluency tends to be a latent gene, so to speak, and so it is harder for many people to grasp and manipulate analytic metrics.