Thursday, December 12, 2013

How the USTA Determines Your End of Year Rating

Year End Ratings came out earlier this month.  

The age old question.  How does the USTA "computer" determine who gets bumped up, who gets bumped down, and who stays at the same level?  Many people believe it to be random, that it doesn't make any sense, or that there is some magic way to "beat the system."

From 1999-2001 I was a USTA NTRP Verifier.  That meant I was trained in how the NTRP works, what to look for in players to determine their "real" rating, and was certified to conduct NTRP verification clinic which the USTA no longer does anymore.

In order to understand how the NTRP system works, you must first understand the term DYNAMIC NTRP RATING. Every player in the NTRP system, both the computer and self rated players, have a dynamic NTRP rating.  It is dynamic because it changes with every match you play, AND with every match your opponents play.

Being a 3.0 rated players does not mean your dynamic NTRP is 3.0, in fact there is an extremely low probability that it is. A 3.0 player's Dynamic NTRP is 2.61-3.10.

2.5 - 2.11-2.60
3.0  - 2.61-3.10
3.5  - 3.11-3.60
4.0 - 3.61-4.10
4.5 - 4.11-4.60
5.0 - 4.61-5.10

When a player self rates, they are placed in the middle of the above ranges, and their dynamic rating starts there.

Only the following matches count toward your rating -

Adult 18+ Gender leagues
Adult 40+ Gender leagues
Adult 50+ Gender Leagues
Senior Adult Gender leagues

Mixed doubles ONLY counts if all you play is Mixed doubles.  And these ratings have an "M" after them, and are treated like a self-rated rating ("S") for the purposes of disqualification in Adult Gender leagues.

NTRP Tournaments ONLY count if all you play are tournaments. These ratings have a "T" after them, and are treated like self-ratings ("S") for the purposes of disqualification in Adult Gender Leagues.

I will come back to disqualifications in a minute.  I need to explain to you how your dynamic rating changes with each qualifying match you play.

When you play a match, and the captains have entered the results online, the computer knows you, who you have played, if it was singles or doubles, and the dynamic ratings of every person involved on the court.

If you played a singles match, the computer compares your dynamic rating with your opponent's and plugs them into an algorithm and spits out the expected score.  Example my NTRP rating is 4.41 and I play someone whose NTRP rating is 4.30.  The computer plugs our ratings into the algorithm and determines I should have won the match 6-4, 6-3.  If the expected score is met, no one's dynamic rating is affected by the result of this match.  If my opponent loses, but loses by a score BETTER than than expected score, their dynamic rating will go up a few points, and mine will go down an equal amount.  If they win, theirs will go up even more, and mine will go down an equal amount.  If I win AND beat the expected score, my dynamic rating will increase based on how much I beat the expected score and my opponent's dynamic rating will go down an equal amount.

When you play doubles, the computer adds your dynamic rating and your partner's dynamic rating, and then does the same with your opponent's dynamic ratings.  It then determines an expected score based on the algorithm.  The rest is identical to the singles description above..

So you can see WINNING is not what causes your dynamic rating to increase, nor is LOSING what causes your dynamic rating to go down.  It is all about did you do better or worse than the expected score the computer determined.  This is why you can lose all your matches and see your rating go up, and why you can win all your matches and have your rating go down.

So as you play Adult Gender League, your rating changes throughout the season.  75% of your rating is determined by how your results compare to the computer's expected results of your matches, and 25% of your rating is determined by your opponents' results against their opponents.  This means that as your opponents' dynamic ratings improves, yours does also, and conversely, if your opponents' dynamic ratings decrease with each match, yours goes down also.  This is how the algorithm determines HOW good your result over someone is.  Example, On day one of 4.5 league, I play Bob, and beat the expected score handsomely, and Bob had a higher dynamic rating than I.  Initially this looks lie a great win.  However, as the season progresses, Bob does not meet or surpass ANY expected scores for the remainder of the season, and consequently his dynamic rating goes down with each match.  Now his dynamic rating is below my own.  Now my result the first week, does not look so great, and my dynamic rating will decrease.  Conversely, If Bob beat every expected score for the season, his dynamic rating would be increasing, and that result I had in week one against him start to look even better.  My dynamic rating will increase because of this.

Many of you that play league will notice that when the USTA releases the "pre-bump" list each year, that sometimes players on that list don't actually get bumped up when the end of year ratings come out.  I know a few players that as happened to.  It is because Nationals are going on and your opponents' results matter at that competition.  If your dynamic rating is very close to the edge, the four matches at nationals that your opponents play could make or break you..    

Now you know how your dynamic rating is determined, and you know the range of dynamic ratings for each year end rating.

At the end of the League year,  you will get a year end rating.  It will either have a "C" for Computer Rating, net to it or a "B" for Benchmark Player next to it.  A computer rating means you generated a year end rating and did not win the local league at the level of your new computer year end rating. A Benchmark Player is someone who DID NOT GET BUMPED UP but remains at the same level, yet was on the team that won their local league.  No computer rated or benchmark player can ever be disqualified from league competition going forward.

Now I'd like to discuss the differences in the Self rating (S), Mixed only rating (M), and the Tournament only rating (T), as they pertain to Adult Gender League play.

Self Ratings, Tournament ratings, and Mixed only ratings are treated identically by the USTA as it pertains to Adult Gender League play.  All three ratings are subject to the USTA 3 strikes and you are out policy.  Only Self ratings, tournament ratings, and Mixed only ratings are subject to the 3 strikes and your out policy for disqualification.

3 strikes and you're out is simple.  If you have one of the three rating types mentioned above and you have 3 wins that beat the expected score   by an amount determined by the computer algorithm, you will be automatically disqualified from the current level of competition, and all your wins for your team are vacated.  This can ave tremendous impact on what team ends up winning the local league.  A myth, is you must have three wins by 6-2, 6-2 or better and that those matches are all considered strikes.  Rather, it is by how much you beat the expected score.  You meet the computer's threshold 3 times, you get DQed.

Self rated, tournament rated, and mixed only rated players can also get DQed if their dynamic rating goes .10 over the maximum dynamic NTRP for the level they are playing.  If, for example, a self-rated 3.0 player's dynamic rating exceeded 3.20 (remember the range for 3.0 id 2.61-3.10) during the season, he or she would be automatically disqualified, all their wins vacated, and they would be forced to play at 3.5 the rest of the year.  This usually results in the player not playing the remainder of the Adult league season.

Final thought.  You will never be able to find out your Dynamic NTRP Rating.  The USTA does not want people to know it.  The only way you can hope to find it out is if your team makes it to Regionals, Sectionals or Nationals and you or someone you play gets challenged because the other team thinks they are at the wrong level.  Only Self rated, Mixed only rated, and Tournament rated players can be challenged.  If this happens, you might be lucky enough to see your dynamic rating on a sheet of paper next to your name as the USTA officials determine whether or not to disqualify someone..Aside form that, you will always be in the dark about your dynamic rating, and all your teammates' dynamic ratings, and your opponents' dynamic ratings.

6 comments:

Unknown said...

Thanks Matt! This is the best explanation of the dynamic rating that I have ever seen, you rock!

joshL said...
This comment has been removed by the author.
Marie Massey said...

Great information. I was wondering if I just got bumped up for this year and I am seeing my dynamic rating above the line on Tennisrecord and below it on TennisLeagueStats, would USTA bump me back down after only the first season at the new level?

Dantana said...

Any new info about dynamic DQs in 2021? there are a lot of self-rated players in my league (and some on my team) ... but no one seems to have been DQd yet. Is it true that a self-rated player vs. a self-rated player can't get strikes?

Unknown said...

Thanks-can you only appeal to the computer or can you appeal to a person? And if I want to appeal to move up what are the determinants?

Unknown said...

Thanks-can you only appeal to the computer or can you appeal to a person? And if I want to appeal to move up what are the determinants?