Investors—or people generally—find it difficult to think in terms of probability. A quote from a recent ThinkAdvisor article on probability is instructive:
In multiple studies (most prominently those by Edwards and Estes, as reported by Philip Tetlock in his book Expert Political Judgment), subjects were asked to predict which side of a “T-maze” held food for a rat. The maze was rigged such that the food was randomly placed (no pattern), but 60% of the time on one side and 40% on the other. The rat quickly “gets it” and waits at the “60% side” every time and is thus correct 60% of the time. Human observers keep looking for patterns and choose sides in rough proportion to recent results. As a consequence, the humans were right only 52% of the time—they (we!) are much dumber than rats. We routinely misinterpret probabilistic strategies that accept the inevitability of randomness and error.
Even rats get probability better than people! It is for this reason that a systematic investing process can be so valuable. Away from the pressure and hubbub of the markets, strategies can be researched and probabilities investigated and calculated. Decisions can be made on the basis of probability because a systematic process incorporates the notion that there is a certain amount of randomness that cannot be overcome with clever decision-making.
Ironically, because humans have sophisticated pattern recognition skills built in, we see patterns in probability where there are none. A systematic investment process can reduce or eliminate the “overinterpretation” inherent in our own cleverness. When we can base our decisions only on the actual probabilities embedded in the data, those decisions will be much better over a large number of trials.
Good investing is never easy, but a systematic investing process can eliminate at least one barrier to good performance.