Goodhart's Law
Not about archery — about any metric in any system. When you measure something to understand it, it stays true. The moment that measure becomes the target to optimize, it warps. Test scores stop reflecting learning. KPIs stop reflecting performance. The map eats the territory. Optimization corrupts the very thing it measures.
When a measure becomes a target, it ceases to be a good measure.
systems-thinking metrics optimization
Source: Charles Goodhart