From my back of the envelope calculation, you should be getting rejected at a minimum 1/e ~36% (that's the failure rate due to random chance in a perfect system

From my back of the envelope calculation, you should be getting rejected at a minimum 1/e ~36% (that's the failure rate due to random chance in a perfect system). Max rejection rate cannot be found due to a tendency to infinity. Key takeaway - don't let your failure rate get below 36%.