- home field advantage is real (in most if not all sports);
- its primary (sole?) cause is biased officiating (the bias likely being unconscious); and
- the magnitude of the advantage is an increasing function of crowd size.
As a (non-rabid) sports fan, and having done a bit of low-level officiating myself, I found the conclusions interesting; but I mention it here because the studies it cites illustrate nicely how to do solid, persuasive statistical analysis using observational data. It's a good example of what some of us are now calling "descriptive analytics" done right.