Thread below describes irregularities in counts and percentages of votes for Biden in Milwaukee wards between values posted as of 4 AM Wednesday night ( https://web.archive.org/web/20201104040300/https://county.milwaukee.gov/EN/County-Clerk/Off-Nav/Election-Results/Election-Results-Fall-2020)and later in the day when Biden took the lead. But it doesn't establish fraud. I think I have that now. https://twitter.com/toad_spotted/status/1324377988499210240
This a Blant-Altman or level of agreement plot. It shows relationship between two measures- the number of votes for Biden by ward at 4 AM and later. From this, you can see a tight correlation between the mean of the late/early votes and the number of "extra votes" added later.
But that's not what's most remarkable about that plot. For a group of Wards, the number of "extra votes" is a perfectly shaped line. They added votes- for a subset of wards only as a perfect linear function of the average of the totals they were aiming for and the initial count.
That may not be the only thing going on- other wards may have had other amounts added- see this shorter "line" for a smaller group of wards. But I think this establishes convincingly that not only was there fraud, it was done systematically across multiple wards.