Are Cautions Really Going Down?

I honestly cannot help it – scientists are naturally skeptical.  If you make an assertion, I will have to question you on what data you have that supports it.  This is second nature to the people I work with, but I realize it is damned irritating to non-scientists (aka “normal”) people.

So when I started reading everywhere that “cautions were down 35%”, I had to go look into it.  This is a preliminary post – more detailed analysis will follow as soon as I’ve read my students’ final projects and gotten comments back to them.

First, let’s talk statistics.  Reliable statistics require large numbers.  It drives me nuts when people extrapolate from the first few races of the year.  You can’t claim much on the basis of five data points.  Even the top quark required seven (if I remember right – they did get more after they announced they’d found it).

The stock market fluctuates up and down.  Everyone except people who are thinking about retiring ignore the short-term fluctuations and focus on the long-term trends.  What do the data say about cautions in NASCAR?

I picked five tracks to analyze in this first round:  Martinsville, Texas, Talladega, New Hampshire and Atlanta.  The first four represent a range of track types, while the last was chosen to see whether the cautions were “cookie cutter-like”.  I first plotted the number of cautions as a function of year for all the tracks together.  If cautions are decreasing, we should see a general trend downward.  Here’s what I got:

Not much of a clear trend, huh?  If anything, it looks like the overall trend (since 1950) is going up.

Thinking it might be unfair to use really old data, I decided to focus on 1997-2012.  I plotted all five tracks on their own graph for just those years.  I’m sorry for the color – those are the defaults on Origin.  I will change them when I do a full post.

What do you think?  I might buy a downward trend for Texas, but it’s hard to make that argument for the other tracks. Martinsville went from 18 in the last race of 2011 to 7 this year – that’s a 61% drop right there — but if you compare it to the Spring race (and an argument can be made for comparing Spring to Spring and Fall to Fall), that race had only 11 cautions.  That’s a drop of 36.3%.  there is a wide gap between those two figures.

Just for fun, I took the historical data for the three tracks with long records.  Here they are:

As I said, I’ll follow this up with more extensive analysis, but I wanted to get the data out there ASAP.