Goodhart's Law in BJJ: When Metrics Backfire

AI-generated writing.

Goodhart’s Law states that when a measure becomes a target, it ceases to be a good measure. EBI illustrates this: the format was designed to incentivize submissions, but competitors now deliberately drag matches into overtime, believing their finishing odds improve there — producing the opposite of the intended effect.

The cobra effect shows the same failure more sharply. Colonial India reportedly offered a bounty on cobras to reduce the snake population; people responded by breeding snakes for the bounty, then releasing them when the program ended. A well-intentioned incentive created a profitable new behavior that made the problem worse.

The BJJ application: chasing submissions in training leads to Hail-Mary offense and escapes rather than positional fundamentals. The fix isn’t to stop setting targets but to revisit them regularly — checking whether the measure is still tracking the actual goal it was meant to serve. The nail factory example captures the same failure mode from a different angle.