Simulating 2021 USTA League Nationals - 18 & Over 4.5 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.

We now enter the second weekend of Nationals, and the 18 & Over 4.5 level is being played in Surprise, AZ.  Here is what is likely to happen for the 4.5 men.

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.

Teams: 15 (Hawaii was listed but now isn't)
5+ undefeated: <1%
4 undefeated: <1%
Tie for 4th: 76%
Size of tie: 4 - 31%, 5 - 24%, 3 - 19%, in theory could be 12!
Sets tie-breaker: 24%, 2 teams 68%, 3 teams 27%
Easiest schedule: 4.42
Toughest schedule: 4.49
Likely semi-finalists: SoCal, Florida, MoValley, Mid-Atlantic
Contenders: PNW, Eastern, NorCal, Texas, New England, Midwest, Southwest, Intermountain, Southern

Like the 40 & Over 4.0 men, there could be a huge tie at 2-2 for the last semi-final spot with 13 of the 15 teams having a better than 20% chance of making the semis.  Realistically, just 9 have 30+% chance, and 5 have a 40+% chance.

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.