Simulating 2021 USTA League Nationals - 18 & Over 5.0 Men

As I did in 2018 and 2019, I will be doing simulations of each Nationals to predict who the most likely four teams are to make the semi-finals, and also look at other interesting things that may occur.  In the two years I've done this, the simulations have done a pretty good job predicting who would advance to the semis including having all four teams predicted correctly several times.

Why do these simulations you ask?  The primary reason is that the format for USTA League Nationals is now a flight-less random round-robin where each team plays four other random opponents.  This introduces significant variations in schedule strength, the possibility of an undefeated team not making the top-4, and teams vying for the top-4 perhaps not having played head-to-head and unfortunate tie-breakers being used.  The simulations aim to educate folks on how it all works and look at what may happen.  Also see this write-up for some things to know about Nationals.

Nationals is just getting going this weekend, the 18 & Over 5.0 event being held in Phoenix Arizona.  Here is what the simulation says is likely to happen for the men's side of things.

As a reminder, my simulations are done using my Estimated Dynamic NTRP Ratings and looking at the average rating for the top group of players on each team, the actual schedule each team will play, and then doing a million simulations of the matches with some random variation in each team's expected result.

This event has just 12 teams and as such there is a schedule where there won't be more than four undefeated teams, less than 1% chance of four undefeated, and just a 6% chance of three.

That chance is 62%, that there will be a tie for the last spot (3-1 or 2-2) and it come down to tie-breakers.  The most likely size of the tie is a four at 34%, but five is very high at 25%, and three is 25% too.  The chances of larger ties diminish pretty quickly, but a 10-way tie is theoretically possible, but it appears a multi-way tie is a very high probability and it could be reasonably large.

Should there be a tie on team record, it comes down first to who has the best court record, then head-to-head (if applicable), then to who lost the fewest sets, then who lost the fewest games, and finally percent of games won.  There is a 26% chance it comes down to the sets lost tie-breaker, and there is a 62% chance that is between two teams and a decent 30% chance it is between three teams,  If the controversial tie-breakers are going to come into play, this is the likely spot.

The schedule strengths do vary a bit, the team with the easiest schedule having an opponent average of 4.78 while the team with the toughest schedule having an opponent average of 4.88.  This leads to an easier road for some teams than others, two of the predicted semi-finalists getting there due to an easier schedule.

So who is most likely to come out in the top-4?  Southern, NorCal, Eastern, and Mid-Atlantic are solid choices.  Pacific Northwest is lurking, and Texas , Intermountain, and Florida ready to step in.

For those interested, I offer a variety of reports to make Nationals more fun and help captains prepare.  I have a Simulation Report that has all of the details of the simulation including the average ratings for each team, each team's schedule strength, the most likely record for each team, and the chance of each possible record for each team.  I also offer reports to help teams scout opponents in more detail, both a Flight Report with full roster averages, top-8 averages and played by court averages for each team, as well as full Team Reports with detailed ratings for each rostered player and stats who who plays with who and on which court and how they do together.  Contact me if interested in any of these reports.