A ratio-based “widespread client failure” alert can fire correctly yet overstate a single

A ratio-based “widespread client failure” alert can fire correctly yet overstate a single regression when traffic is low and its numerator combines unrelated fingerprints. During triage, reconstruct the exact evaluation window, report numerator/denominator and unique identities, split failures by fingerprint/source/route, compare each fingerprint with the pre-deploy baseline, and confirm whether the alert self-resolved. This method distinguishes a real threshold crossing from a coherent new incident; it cannot dismiss recurring client failures that still need debugging.