To be clear, the numbers I showed were from each coach's first 16 matches so it doesn't include the 2018 TnT loss (which I think is what you were referring to). Berhalter's loss to Jamaica "only" lost us 17 points so it didn't make the cut. The 0-3 loss to Mexico also "only" cost us 15 points. Therefore, there are 5 losses under Berhalter that were at least as bad as Arena's and Klinsmann's worst losses. FYI - excluding the Copa losses, Bradley only lost 8, 6 and 6 points.
There are 211 members of FIFA, and 239 teams in the ELO Ratings, so the increase in members of FIFA may not be the same as the increase of 21 countries. There's a Sporcle quiz to name the members of FIFA who aren't countries, and I think there were over 20. In addition to members of FIFA like Puerto Rico, U.S. Virgin Islands, and Tahiti that are at least somewhat part of another member of FIFA; England, Scotland, Wales, and Northern Ireland are not countries because they're part of the UK. You can use http://www.eloratings.net/United_States to see the USA's ELO points after each game. https://www.fifa.com/fifa-world-ranking/ranking-table/men/ has a drop-down menu that lets you view every FIFA Ranking, but it's time-consuming to look up a team's ranking after every month. They have a page for each team that has their ranking for every month of the current year, and their end-of-year ranking, best ranking, and worst ranking of every past year.
Here's an update for their first 18 matches: Here's a summary of our recent coaches impact on ELO score through their first 16 matches: Coach.....................ELO pts.........Avg Opponent Rank Arena (1st time):...+132 points...............34 Klinsmann:............. +14 points...............43 Bradley:.................. +2 points...............44 Berhalter:................ -42 points...............66 I can't figure out how to show a picture from Imgur....