Election Night Needles
One great place to watch is Election Needles by Nate Cohn.
Cohn explains the methodology and reasons for those states in Needle Update: What to Expect on Election Night
Our three “needle” battleground states will be Florida, Georgia and North Carolina, for a simple reason: These states give us the kind of data we need to offer accurate estimates of the final vote. They report the results in unmatched detail, so our estimates might even be better than usual in these states.
Better still, these states count their votes relatively quickly. They have experience with absentee voting, and they close their polls early in the night. Much of the vote in North Carolina and Florida is expected to be counted by 8 p.m. Eastern.
The core issue is that election results early in the evening are usually not representative of the final vote. Sometimes, only one kind of vote — like mail-in ballots or Election Day votes — has been counted. Other times, reported results are from only one part of a state. You would need to be a bit of an expert to figure out whether a 20-point Trump lead in the early Virginia results is a) to be expected; b) a sign of a Trump landslide; c) actually a sign of an unexpectedly large Biden win.
So why Florida, North Carolina and Georgia?
They give us the results broken down by vote method. We’ll have a very good estimate of what kinds of votes are left, in addition to where. Other states just don’t release the data in the level of detail that we need.
Better still, all three states release copious data to let us make these estimates particularly well. They will release the results not only by method, but also by precinct — a much finer level of geographic detail than we’ve typically had. This means that we’ll have a good idea whether the remaining Election Day vote in Miami-Dade County is in a Democratic or Republican part of the county.
538 Election Live Blog
Also consider 2020 Election: Live Results And Coverage by Nate Silver and the 538 staff.
Election Night Scorecard
Finally, please consider my Election Night Scorecard: Here's What to Watch
There are 12 key states and quite a few will be fast
Florida, Georgia, North Carolina, Ohio, Texas, and Wisconsin will all likely be fast.
North Carolina and Ohio have reservations depending on how close the election is.