Pareto Principle
Around 20% of what you do often produces 80% of the result. Do you know which 20%?
The Pareto Principle (or 80/20 rule) is the observation that most outcomes come from a few key causes.
In business, a handful of clients generate most revenue. In fitness, a few core habits drive most health. The point isn’t the exact ratio, it's identifying the high leverage thing to do first and prioritizing that.
Origin
Named after the economist Vilfredo Pareto, who observed in the 1890s that about 20% of Italy’s population owned about 80% of the land. Joseph Juran later applied the pattern to quality control and gave it Pareto’s name.