Wednesday, May 7, 2014

A star lefty, in decline

Over the last three years, including thus far in the 2014 season, this highly touted ace has seen his ERA rise almost a full earned run between both 2012 and 2013, and 2013 and 2014, and is now solidly below average. He's been victimized by a decline in ground balls (53% in 2012 to 42.6 in 2014) and a lot more fly balls leaving the park (15.7% in 2014, compared to a 9.4% on his career).

On baseball fandom, modern society, and poverty

This is a rather random observation, starting with a spectacular infographic from the New York Times which mined Facebook information to map out which places root for which baseball teams.Seriously, go play around with that map. Right now.

Not to get overly dramatic, but the map of baseball fandom can really lead to some conclusions about America as a whole. Before we start wildly speculating, an important caveat for this map. The percentages are calculated based on how often baseball teams are being mentioned in a Facebook post. It does not look at overall levels of support for baseball compared to other sports or activities, so those percentages should be read as numbers specific to posts regarding baseball.

First, the west is settled by transplants, who are taking their previous allegiances with them. People living close to west coast teams at 50-60% support in their highest counties, whereas east coast teams like the Red Sox, Yankees, Braves, and Phillies are in the 70-80%. This isn't surprising; people aren't moving to Boston from California too terribly often, at least in comparison to migrants in the other direction.

The Halo Effect
Red Sox support surrounding Boston (darker=higher)
 Additionally, we can see some interesting effects surrounding major cities, such as Boston. I've only shown Boston as an example, but similar patterns surround St. Louis and Philadelphia. What we can see is that the areas surrounding the city actually have higher support for the local team than the city itself. If folks from elsewhere in the country are moving to these areas (and bringing their baseball allegiance with them), they're more likely to move into the major metropolitan areas, rather than the suburbs. So what we see is a halo of higher local team support surrounding the city center.

Tigers support surrounding Detroit (darker=higher)
Not all cities follow this pattern though. Take Detroit, for example. Instead of having a lower level of support in the city center, we see a halo of lower support surrounding the city center, which has higher support than the surrounding suburbs. We can use the level of support for the local team as a proxy for the amount of people moving into the area from other parts of the country. So in Boston, if you're moving into the area, you're staying close to the city, but if you're in Detroit, you're moving into the suburbs north and west of the city. This difference shouldn't be too surprising, as Detroit is a classic example of white flight from a major metropolitan area.

Local Support and Poverty
We can see in Detroit a higher poverty level in the core city center, compared to the surrounding suburbs. This is a pattern you see in almost every city in the US, but it is particularly marked in Detroit. I think the implications are simple - if an area has a very high poverty level, new transplants to the city are less likely to move there, which in turn will maintain higher levels of support for the local team.

This pattern also holds true in western cities, such as Los Angeles. It shouldn't be too surprising that we see higher poverty rates in city centers - this is a pattern that holds true in all cities across the country, even in very high income cities like San Francisco. However, the association between poverty and home team support seems to be more marked in poorer cities overall.

If you'd like to look at poverty rates in the US, here is another nice infographic from the New York Times.