in AA, several districts had both teams advance, and other districts had 0 wins in the opening round of regionals. I think that says more about the strength of certain districts than it does about upsets.
Districts 2,4,8,14, and 16 all had two wins. Districts 1,3,7,13,15 had no wins.
District 9 could have two wins and D 10 no wins if Lipscomb wins today. So far only 4 districts split 1W - 1L.