Wednesday, September 29, 2021

Simulating 2021 USTA League Nationals - 18 & Over 3.5 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.

Nationals is just getting going this weekend, the 18 & Over 3.5 event being held in Surprise 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.

With 16 teams at the event the USTA never creates a schedule that can avoid more than four undefeated teams, and there is a  less than 1% chance of five undefeated.  There is only a 7% chance of four undefeated, so this means a very competitive event and a good chance of teams at 3-1 vying for the last advancing spot.

That chance is 89%, that there will be a tie for the last spot (4-0 or 3-1) and it come down to tie-breakers.  The most likely size of the tie is a 4 at 28%, but three is pretty high at 25%, and five is 22%.  The chances of larger ties diminish pretty quickly, but an 11-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 27% chance it comes down to the sets lost tie-breaker, and there is a 68% chance that is between two teams and a decent 27% 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 3.51 while the team with the toughest schedule having an opponent average of 3.61.  This leads to an easier road for some teams than others, one of the predicted semi-finalists getting there due to an easier schedule.

So who is most likely to come out in the top-4?  Missouri ValleyFloridaNorCal, and Texas are solid choices, but a six-way tie is likely for 2nd thru 7th with Mid-Atlantic, Midwest, and Intermountain all having a greater than 50% chance of making the semis.

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.

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