Checking USTA League self-rated women by section - Who sandbags or overrates?

I wrote a few days ago about trends with self-rated players being bumped up or down at a national level.  That revealed some interesting observations, notably that men seem to underrate a bit at 3.0 and 3.5 levels while women tend to overrate at the same levels.

But that is Nationally.  Do the same trends hold at the section level?

You knew I couldn't leave that one alone, so we will start with the women and look at the breakdown by section.  As a reminder, these charts are showing the number of players by level that self-rated in 2015 and stayed the same at year-end as well as are bumped up and down.  On each bar the number shows the percentage for each category by level.

As a refresher to start, here is the national chart for the women:

Now, we'll just go through the sections alphabetically.

Caribbean:

A vast majority of players in the Caribbean self-rate at 2.5!  And nearly 2/3 of these players arguably underrate as they get bumped up at year-end.  Now, it is easy to improve significantly at 2.5 and it may be natural for beginners to self-rate at 2.5, but this is still a remarkable statistic.  Interestingly, it appears more women self-rate at 3.5 than 3.0, and unlike the national trend more women get bumped up than down.

This whole chart in fact looks more like the men's chart where one could conclude there is sandbagging going on.  Is there sandbagging amongst the women in the Caribbean?  Is this in part why they won 18+ 3.0 Nationals last weekend?

Eastern:

This chart looks a lot more similar to the national chart, although at 3.0 a few more self-rated women are bumped up than down, but at the 3.5 level, hardly any get bumped up.

Florida:

Florida looks even more like then national chart, a trend of a few more self-rated women being bumped down than up.

Hawaii:

Another ratings "island" so to speak like Caribbean, there is again more of a trend towards bump ups, even into the 4.0 level.  But a lot more players self-rate at 3.5.  Perhaps Hawaiian women also underrate slightly?

Intermountain:

This section also has a lot of players self-rate at 2.5, but doesn't have a huge number of them get bumped up.  And at 3.0, 3.5, and 4.0 levels, a far larger number of self-rated women get bumped down than up.  So far, this is the most extreme case of potential overrating.

Mid-Atlantic:

Mid-Atlantic has a slight bias towards underrating, particularly at 3.0, which also could have contributed to making the final at 18+ 3.0 this past weekend.

Middle States:

This section is pretty balanced, just a modest number more self-rated women being bumped down at 3.5 and a larger number at 4.0.

Midwest:

Midwest has a slightly larger number of 2.5s bumped up, and at 3.0 does have a few more bumped up, but goes back to the national trend of more bump downs at 3.5 and 4.0.

Missouri Valley:

This section is similar to Midwest with more 3.0s being bumped up, but more 3.5s and 4.0s being bumped down.

New England:

New England has a lot of women self-rate at 3.0 and they do it quite accurately it appears.  The general trend at other levels applies.  With so many players joining at 3.0, it is perhaps not a surprise they made the semis at 18+ Nationals this year.

Northern California:

In NorCal we see some underrating at 3.0 like a few other sections and a lot of 2.5s bumped up, but otherwise like the national averages.

Northern:

Northern is interesting as the vast majority of women self-rate at 3.5 unlike most others.  More of those self-rated 3.0s get bumped down that up though.

Pacific Northwest:

In the PNW, we see a few more 3.0s bumped up, but a lot more self-rated women 3.5s bumped down.  They also made the semis at 3.0 with the slight bias of more bump ups.  But PNW won the 3.5 level this year where a lot of players got bumped down last year.

Southern California:

SoCal also has more 3.5s, but not like Northern, and at 3.0 a lot of players, nearly a 1/3, get bumped up.  Perhaps more should be self-rating at 3.5!

Southern:

Southern looks pretty normal, just a few more 3.0s bumped up, but the section is so large you'd expect it to look a lot like the national averages.

Southwest:

Southwest has a lot of 2.5s bumped up and interestingly goes against the national averages at both 3.0 and 3.5 with a few more self-rated women bumped up than down.

Texas:

Texas look fairly normal and close to the national averages, just a few more bumped up at 2.5 and 3.0.

So we see a few surprises, and some of the sections that seem to underrate at 3.0 and 3.5 did do well at Nationals this year.

What do you think?