Another look at what NTRP rating combinations works best in Mixed 18 & Over? More Interesting Tennis League Stats

I've been looking at how different combinations of levels do in the 55 & Over Adult and 18 & Over Mixed, and just took a deeper dive on 55 & Over, so the same deeper dive on Mixed is in order.

The general observation has been that unbalanced pairs, e.g. a 4.5 and 3.5 in an 8.0 flight, tend to win more often than not, and this deeper dive will take a look at if this is actually expected or not based on the current ratings of the players.

The deeper dive on 55 & Over revealed that while the unbalanced pairs do win more often, they are always expected to, and often fall short of the expected winning percentage.  This may indicate a selection bias of sorts, where it is possible that only stronger players at their level opt to play as an unbalanced pair, thus skewing the stats in their favor, and there is not some inherent advantage to unbalanced pairs.

So on to taking a closer look at Mixed.  Specifically, I narrowed the matches analyzed to only those where I had an established rating for all 4 players and then looked at not just how often unbalanced pairs won, but how often they were expected to win.  The results were certainly interesting, and a bit different from what we saw for 55 & Over.

Note, the actual winning percentages are slightly different from the earlier post because some matches where the players didn't all have ratings have been filtered out.

For each level/gender below, I'm using 2022 18 & Over Mixed league data again and showing the percentage of the time the unbalanced pair won, followed by the percentage of the time the unbalanced pair had the higher combined ratings.  When the actual is higher than the expected, the unbalanced is overachieving, and when the actual is lower than the expected, they are underachieving.

The ratings used for this analysis are my Mixed Exclusive Estimated Dynamic NTRP Ratings I use for doing the various individual, team, and flight reports I offer.  The pairings are showing the male then female levels.

Starting with 6.0:

• 3.5/2.5 vs 3.0/3.0 - 52.0% actual, 57.1% expected - underachieved
• 3.5/2.5 vs 2.5/3.5 - 53.7% actual, 41.1% expected - overachieved big
• 2.5/3.5 vs 3.0/3.0 - 48.0% actual, 59.3% expected - underachieved big

The 6.0 level can be tricky with a lot of new/unknown players at times, but we see the pairs with the higher rated male player win more often, and this is especially true when it is a 3.5 male vs a 2.5 male and the 3.5 male really overachieves vs expected.

But like I said, 6.0 is tricky, so on to 7.0 where players are a little less volatile:

• 4.0/3.0 vs 3.5/3.5 - 58.7% actual, 56.4% expected - overachieved a bit
• 4.0/3.0 vs 3.0/4.0 - 56.3% actual, 51.7% expected - overachieved
• 3.0/4.0 vs 3.5/3.5 - 49.7% actual, 53.3% expected - underachieved

We again see the pair with the higher rated male wins more often, and we also see some over achievement for the 4.0/3.0 pairs.

Next, 8.0:

• 4.5/3.5 vs 4.0/4.0 - 57.8% actual, 54.9% expected - overachieved
• 4.5/3.5 vs 3.5/4.5 - 52.4% actual, 48.9% expected - overachieved
• 3.5/4.5 vs 4.0/4.0 - 54.2% actual, 53.2% expected - overachieved a bit

The trend of unbalanced pairs overachieving continues by a decent 3-4% margin for the 4.5/3.5 pairs.

Next, 9.0:

• 5.0/4.0 vs 4.5/4.5 - 61.6% actual, 53.6% expected - overachieved big
• 5.0/4.0 vs 4.0/5.0 - 59.1% actual, 55.0% expected - overachieved
• 4.0/5.0 vs 4.5/4.5 - 56.6% actual, 54.6% expected - overachieved a bit

The over achievement for unbalanced pairs is seen here too.

The counts for 10.0 are so low there is no point to doing the analysis here.

Given we see some to significant over achievement for the unbalanced pairs, especially at the higher levels, it may be that there is an inherent advantage in Mixed.  This is perhaps because at higher levels, players are able to employ strategies maximizing the difference in abilities taking advantage of having the stronger player.

It could also be that for the lower level player of unbalanced pairs, only the top players at that level self-select to play, and that gives an inherent ratings advantage over two "average" players on a balanced pair.

What do you think?

What NTRP rating combinations works best in Mixed? More Interesting Tennis League Stats

I wrote yesterday about what ratings combinations work best for 55 & Over Adult play, today, I thought I'd start a refresh of the ratings combination analysis for Mixed I did around 8 years ago.

To start, I'll look at 18 & Over Mixed.  For reference, here is the post I did 8 years ago for the same division.

This time I will include 6.0 and 10.0 levels I omitted last time.  For each pairing I list, the first number will be the male level and the second the female level.

Starting with 6.0:

• 3.5/2.5 pairs beat 3.0/3.0 pairs 52.7% of the time
• 2.5/3.5 pairs beat 3.0/3.0 pairs 49.6% of the time
• 3.5/2.5 pairs beat 2.5/3.5 pairs 56.2% of the time

Here, a slight to significant advantage to unbalanced when the male is the higher rated player.  The 2.5/3.5 is ever so slightly below 50%.

Next up, 7.0:

• 4.0/3.0 pairs beat 3.5/3.5 pairs 58.3% of the time
• 3.0/4.0 pairs beat 3.5/3.5 pairs 50.8% of the time
• 4.0/3.0 pairs beat 3.0/4.0 pairs 55.1% of the time

This is similar to before (60%, 52%, 57%) so that form continues to hold.  Unbalanced with the higher rated male has the advantage, but unbalanced with the higher rated female has a slight advantage too.

Next up, 8.0:

• 4.5/3.5 pairs beat 4.0/4.0 pairs 57.6% of the time
• 3.5/4.5 pairs beat 4.0/4.0 pairs 53.5% of the time
• 4.5/3.5 pairs beat 3.5/4.5 pairs 51.7% of the time

This is a bit different from last time (61%, 51%, 60%) with the unbalanced 3.5/4.5 pairs doing better than before.  Still, unbalanced has the advantage over balanced and unbalanced with the higher rated male stronger overall.

And 9.0:

• 5.0/4.0 pairs beat 4.5/4.5 pairs 59.6% of the time
• 4.0/5.0 pairs beat 4.5/4.5 pairs 56.1% of the time
• 5.0/4.0 pairs beat 4.0/5.0 pairs 58.5% of the time

This compares with 57%, 58%, 51% last time, so a bit different, but the trend holds.  Unbalanced with more frequently, and the unbalanced with the higher rated male do so over the higher rated female.

Last, 10.0:

• 5.5/4.5 pairs beat 5.0/5.0 pairs 27.0% of the time
• 4.5/5.5 pairs beat 5.0/5.0 pairs 62.9% of the time
• 5.5/4.5 pairs beat 4.5/5.5 pairs 66.7% of the time

Note there is so little play at this level that some of the totals for these match-ups are in the single digits so make of that what you will.

Aside from a couple anomalies at the 6.0 and 10.0 levels, the trend continues.  Unbalanced pairs win more often in Mixed.  The advantage is not huge, most of these winning percentages are between 50% and 60%, but it is consistent.

What do you think?  Is this consistent with what you see locally?

USTA League Mixed Participation - A preliminary look at some USTA League statistics for 2023

 I've been doing some mid-year looks at participation for 2023 to get a preliminary idea of what any continued recover post-COVID there is or if the general decline we've observed since 2013 may be continuing.  I even took a look by section, first warm weather sections, then the rest, and saw some sections are declining faster, and a few have actually shown growth.

In doing that analysis, I looked at only the main Adult advancing leagues as I've done that each year and it provides consistency for comparing things year to year.  I thought it would be interesting to also look at Mixed, so this post will dive into that.

For this analysis I'm looking at unique participants during the USTA rating year in the 18 & Over or 40 & Over Mixed leagues.  This is unique participants, not total registrations, so someone playing in both leagues or multiple levels will be counted just once.

Also, since the USTA had a 2-year rating period for 2020/2021 due to COVID, I'm grouping those as a single "year".  As you  might expect, when I've looked at them individually in the past, 2020 was way down, and 2021 recovered some but not all the way to 2019 (or 2022) levels.

Here are the overall participation stats for Mixed!

This may be the first time I've done this for Mixed, so we actually get a view into the years from 2013 and on to see how it compares with the trend in Adult.  From 2013 to 2018, Adult dropped about 7-8% and here it is similar, although the bulk of the drop was in 2018.  There was a slight recovery in 2019 like Adult leagues also saw, but Mixed was a bit larger.  Combining the COVID years also shows a greater bump than Adult, and then a similar drop in 2022.  So overall Mixed participation very much mirrors Adult.

What is interesting is that 2023 is way behind 2022 at this point.  That is alarming at first, but a number of sections run Mixed leagues either in the Summer so just starting, or as early start leagues so still to be played, so much of that gap is due to that.

Another observation is that Mixed obviously requires the same number of men and women on the court, but every so slightly more women participate than men.  My observation locally is that to ensure player availability, teams often have more women than men, so this seems to back that up.

Next, I went ahead and looked at unique participants across Adult and Mixed.  Adult showed 275K in 2013 and Mixed shows 91K, so do these get added together?  Alas no as many players play both so only get counted once when looking at the combined stats.

Here is the chart.

Since the trends are similar in each category by themselves, combined we see the same trend.

It is interesting that in 2013 the combined number is 296K which tells us that about 21K appear to have played Mixed but not Adult that year.  In 2022 it was 243K in Adult and 262K combined so about 19K playing only Mixed.

What do you think?

Note: These are statistics from the data I've gathered for calculating my ratings and generating reports and may not exactly match the USTA's data or they may report numbers using different criteria than I am.

USTA League Regulations Changes for 2024 - Strikes in Mixed?

It is only June 2023, but with 2024 early start leagues beginning in Georgia already, and other areas starting in the late Summer and Fall, the USTA League regulations for 2024 are starting to become relevant.

I have not seen a full regulations document yet, but have heard about a few changes, some National, some section specific, that I think are interesting and IMHO, probably a good thing.

First, it appears that National is going to be calculating dynamic ratings for Mixed in 2024!  This means that self-rates, appeals, and mixed-exclusive players will be subject to strikes from their Mixed play.  This is big and I think will help cut down on some of the abuses of the system we see in Mixed where new players self-rate too low and dominate, but there is very little that can be done to disqualify the players that are clearly out of level.

I have not heard if this will begin with 2024 early start Mixed leagues or only for play during the 2024 rating year, but am working to find out.  I assume that the rating from Adult league play will still be what goes into year-end ratings, but have not confirmed that yet either.  But what do you think?

Second, in most sections, Tri-Level has counted for year-end ratings for a number of years.  Southern has been a hold-out, which could again be abused in some scenarios where players could dominate in Tri-Level for several years using an artificially low year-end level from a prior year.  Well, in 2024, Southern will be including Tri-Level matches in year-end ratings.  Southern will also hold Sectionals for Tri-Level in 2024 which I guess they haven't in the past.

Third and last (for now), also in Southern, a change is being made to the levels for Mixed leagues.  In the past, I believe every section has run Mixed leagues as "combo" leagues, e.g. 6.0, 7.0, 8.0, 9.0, and 10.0, where the players on the court cannot have a combined current level over the level of the flight.  This allows for a 4.5 and 3.5 to play together on an 8.0 team for example.  This gives teams a lot of flexibility, and allows friends and spouses at a variety of levels to play together, but can lead to a pretty wide disparity in ability on the court at the same time, e.g. a 4.0 male with a 3.0 female (or 4.5/3.5 or 5.0/4.0).

Well, for championship year 2024 leagues in Southern, Mixed is going to be straight-level leagues, e.g. 3.0, 3.5, 4.0, 4.5, 5.0, meaning it will be like normal Adult leagues where just 3.5s and 4.0s can be on a 4.0 roster for example.  This will reduce the disparity of abilities on the court, but perhaps put Southern at a disadvantage come Nationals where they will have to face combo-level teams.

There are some side-effects of this of course and I assume they were all considered as some might be perceived as or actual negatives for a number of players.

A simple one is that this restricts the ability for some friends/family/spouses to play together on a team.  A husband and wife that are a 4.0 and 3.0 could play 7.0 before, and now can't play on a Mixed team together.

A more significant side-effect is on participation though.  Where a player could have played on three different Mixed teams at different levels before (e.g. a 4.0 could play 7.0, 8.0, and 9.0), the same player can now play on only two teams (4.0 and 4.5) and will be at a disadvantage one one of them.  This has the potential to reduce participation 33%.  Now, one might argue that there are players that avoid Mixed because of the ability disparity issue and they'll come back and make up the difference, but we'll have to watch and see.

It is worth noting that parts (or perhaps all) of Southern has done 55 & Over leagues as straight-level so this is just making their Mixed leagues consistent with that.  That has worked for them, and Southern has done well at Nationals in this division, so it will be interesting to see how this plays out.

What do you think?

Does the USTA have Mixed ratings and leagues all wrong?

The USTA has a variety of leagues for different ages and genders including Mixed leagues where Mixed doubles are played with each doubles pair being a man and a woman.  Mixed is very popular in some areas and with some players due to the playing opportunities it offers.

In its advancing league format (can progress on to Nationals), the format is to use combined NTRP levels on the ".0", e.g. there are flights for combined levels 6.0, 7.0, 8.0, 9.0, and 10.0.  This means that players at the "mid" levels can play in three different flights at the same time.

For example, a 3.5 player, man or woman, can play 6.0 (with a 2.5 partner), 7.0 (with a 3.5 partner), and 8.0 (with a 4.5 partner) in the same league.  Similarly, a 4.0 can play 7.0, 8.0, and 9.0 at the same time.

Now, this can create can only be called interesting tennis with what are quite unbalanced pairings and players on a court.  Consider an 8.0 match with a 3.5 woman and 4.5 man on one side, and two 4.0s on the other.  Conventional wisdom is that since NTRP levels are not gender neutral and there is in fact roughly a 0.5 gap between a male and female player of the same ability, we could normalize this by adding 0.5 to the men's levels and say this Mixed match is really a 3.5/5.0  pair vs a 4.0/4.5 pair.  This means we have what is supposed to be a competitive recreational match with players from four different levels on the court and one pair three levels apart.

There is nothing inherently wrong with this, but it does make for a different game of doubles than is customarily played in same gender leagues.  Due to the disparity between the 3.5 and "5.0", a competitive opponent is going to mercilessly target the 3.5 as they are clearly the weaker player.  As a result, the 3.5/"5.0" pair may do things like position the 3.5 right on top of the net guarding the alley to dissuade the opponent from targeting her and allow the "5.0" to get all the balls.

Now, part of the reason some people like Mixed is not just because one player can play in three different flights, but because of the range of levels that can be on a team, it allows friends and spouses at different levels to be on a team together that they wouldn't normally be able to.  This tends to make Mixed more of a social league in general, but some take it seriously and deploy the tactics described above to maximize the chances of winning.

I've often thought that Mixed flights should be on the ".5", e.g. 5.5, 6.5, 7.5, 8.5, 9.5, with the max allowed difference being 0.5, thus a 7.5 flight would have 3.5s and 4.0s, which would result in less disparity in ability being on a single court, but still allow a fairly diverse set of players to be on a team.

Some areas actually do have "Combo Mixed" leagues on the ".5", but these are only local leagues and don't advance to Nationals.

What do you think?  Should Mixed be on the ".5"?  If you play in a Combo Mixed league on the ".5", how has it worked out?

The other observation about Mixed is regarding ratings.  The USTA publishes a single rating/level for each player.  If a player plays at least three applicable Adult (same gender) matches, their rating is based solely on those results and no Mixed matches that are played count.  It is only if a player plays just Mixed (three or more Mixed and two or fewer same gender Adult) matches that their Mixed matches are used for their rating, and then only the Mixed results are used and they get an "M" rating/level at year-end rather than a "C".

Part of the reason Mixed matches are kept separate is that, due to the format with the broad spread of abilities, it really is a different game, and/or the USTA does consider it to be more social league and the results to not fairly represent a player's ability.  This is supported by the fact that a player that gets an "M" rating is required to self-rate again to play Adult, so the USTA doesn't really trust Mixed results to reflect a player's ability.

Or they don't want players to tank their Mixed matches in order to manage their rating to prevent being bumped up from their Adult matches.

For many players, this isn't a big issue.  Most players play a fair amount of Adult matches, and more importantly, their results in Adult and Mixed indicate a similar ability, so even if the USTA used Mixed matches along with Adult matches, players likely wouldn't have their year-end level change.

However, there are some that really get into Mixed and play all the levels they can and get on teams with aspirations of going to and winning Nationals.  If these players only play Mixed, they'd get an "M" rating based on these matches and all would presumably be fine.  Unfortunately, some will play Adult also, but only the bare minimum, and they get a "C" rating based on just a few matches.  For those players that really focus on Mixed and that style of game, or worse, those that will not "play their best" in their Adult matches, this "C" rating may not really represent their ability in Mixed.

What this allows is for a player to clean-up in Mixed, perhaps unfairly, while their opponents who play both Adult and Mixed and go all out in their Adult matches, are at a disadvantage comparatively.

It this an issue?  Someone thought so as there is a petition on change.org, "Close the NTRP Rating System Loophole in USTA Leagues", that asks for the USTA to not ignore Mixed match results in calculating year-end ratings.

The petition simply asks for Mixed matches to be included.  I'm sure that could be done, have a single year-end rating that factors in Adult and Mixed, but would that really accomplish what they are after?  Someone could still play Adult to manage their rating down which would offset their excellent Mixed results.  And there might be unintended consequences where someone is bad at Mixed and including those pulls their rating down and they get an artificially low rating for Adult.

Other alternatives would be to:

• Keep calculating Adult and Mixed separately, but have a player's year-end level be the higher of what is calculated for each.
• Keep calculating Adult and Mixed separately, and give a player two levels, one they use to play Adult and one they use to play Mixed.

Both of these options address using one discipline to sandbag to get an artificially low rating for the other, one just forces the player to play at the higher of the levels for all matches.

What do you think?  Is this even a problem that needs to be addressed?  If so, in way?