Real expertise predicated on predictability: no predictability, no expertise

In that article, Don’t Blink! The Hazards of Confidence by Daniel Kahneman, Kahneman is making the suggestion that in systems that are complex, chaotic, and loosely coupled (ex. stock markets), there is little comprehension about the linkage between cause and effect, so participants are not able to extract useful information and therefore their performance is going to be random. In systems that are simple, stable, and have good feedback systems, practitioners have the capacity to develop and demonstrate expertise and accuracy of forecasts, i.e. their performance will be predictable.

The corollary insight, such as it is, is that where you do not have predictable performance, you are likely dealing with a complex, chaotic, loosely coupled system.