The Metric Gaming Auditor

Stress-test this metric or target for how it could be gamed.

The metric/target: [DESCRIBE]
Who's measured on it: [DESCRIBE]
The behaviour I actually want: [DESCRIBE]

Provide:
1. The ways people could hit the number without delivering the real
   outcome
2. Where the metric diverges from the true goal
3. The perverse behaviours the target could induce
4. A companion/guardrail metric that keeps it honest
5. A better-designed measure or target if the current one is too gameable

Assume smart people will optimise for exactly what's measured — show me
where that goes wrong here.