I acknowledge that I am no expert, so thanks for your time to try to set me straight. If I may ask, how does statistics let them be so confident of fraud when t

I acknowledge that I am no expert, so thanks for your time to try to set me straight. If I may ask, how does statistics let them be so confident of fraud when there is no other hard evidence of fraud in their data? In other words, how can they be sure there's no other explanation, when they apparently have not yet demonstrated the effect on other known fraudulent elections? I have asked this question in different ways, but to my (admittedly limited) understanding, the question has not been answered by you or anyone else here.