Rule of Thumb

Some people get a little antsy about them because they aren’t accurate. The literalist will struggle with a rule of thumb because it’s a general specification not a perfected specification. 

It turns out they are right.  Judging a rule of thumb with a critical magnifying glass misses the value.

Momentum is the reward for trading exactness for rules of thumb.

They are never perfect but very useful… useful because they keep you moving.