Quick answer: Bug count is the easy metric and the wrong one. Tracking bug cost (impact * frequency * fix-time) surfaces what to actually fix.
Bug count is theatrical. Bug cost is the bottom line.
Estimate impact
How many players affected? Per-bug estimate. Weights small bugs less.
Multiply by frequency
How often does it happen? A daily annoyance is worse than a weekly crash.
Add fix-time
Some bugs are quick fixes; others are weeks. Cost includes the engineering investment.
Track per quarter
Total bug cost as a number. Plot over time; improvements visible.
“Tracking cost shapes engineering priorities. Counting bugs doesn't.”
Most studios over-fix small bugs and under-fix big ones. The cost metric corrects the bias.