Over 500 lives were lost in the Boeing 737 MAX crashes, and another 100 in the Amagasaki derailment. What ties these tragedies together? The flawed use of metrics—turning a tool for decision-making into a catalyst for disaster.

Even when lives aren’t at stake, metrics can wreak havoc. Metrics are a double-edged sword. Ignore them, and you risk making decisions based on gut feel alone. Misuse them, and you create bad incentives that sabotage your goals.

So, let’s talk about metrics: what makes them valuable, how to wield them effectively, and—most importantly—how to avoid turning them into traps.