Simulating 2025 USTA League Nationals - 40 & Over 4.0 Men

USTA League Nationals for 2025 continue this weekend!  The schedule is slightly less compressed this year being played in five instead of four weekends, but still more compressed than past years where it was seven weekends.

This weekend has three events, 18 & Over 4.5 in Surprise, 40 & Over 3.0 in San Diego, and 40 & Over 4.0 in Scottsdale.

I've been doing simulations since 2018 and have found that the four semi-finalists are usually in the top six to seven projected teams, and more often than you might think, I project the four semi-finalists perfectly.  There are surprises sometimes and a mid-pack team overachieves and advances, that is why the matches are played on the courts and not on a computer.  Still, it is interesting to do these simulations and see how the projections do.

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.

Because of the fairly compressed schedule, I likely won't have the time to do previews/simulations of all events, but will try to do a few.  Let me know which you'd like to see!

Like I did last year, I'll be primarily just giving the data from the simulation and not writing a bunch of words.  Most of it is self-explanatory, but the favorites and contenders will be listed in alphabetical order.  The strengths are based on played averages.  Contact me if you want to learn more.

On to the projections from the simulation, here is the 40 & Over 4.0 men.

Teams: 17

Chance of 3 undefeated: 37%
Chance of 4 undefeated: 14%
Chance of 5 undefeated: 1.4%

Chance of 6 undefeated: <1%

Chance of tie for last spot / most likely size: 83% / 4
Strongest / weakest team strength: 4.10 / 3.86
Toughest / easiest schedule: 4.01 / 3.91
Favorites: Florida, Middle States, Midwest, Texas
Contenders: Missouri Valley, Southern

Have a chance: NorCal

This event appears pretty top heavy with four pretty clear favorites and thus a decent chance of four 4-0 teams.  The overall favorite to make the semis isn't the strongest team, but benefits from the easiest schedule.  There are a few contenders that could spoil it and there is a 1.4% chance of five 4-0 teams.

What do you think?