Let's say I have 5 teams: "a", "b", "c", "d", "e". As we go through the season, I take snapshots of how they rank. I then want to find the earliest point at which the ranking is a "good" predictor of the ranking at the end of the season. How can I measure and compare the accuracy (similarity to the final ranking) of these earlier rankings?
The first think I thought of was to just look at the number of slots that were guessed correctly, but then I can end up at a place where "e"-"a"-"b"-"c"-"d" will count as less accurate that "b"-"e"-d"-"c"-"a" since the latter is at least 20% correct. This feels like the type of situation common enough to have a standard approach, sadly I haven't been able to find one.