Last year I did a post on Zipf's Law, in terms of popularity of chess clubs. But like any good idea/explanation/system it can turn up in other places.
In this link from the American Physical Society, there is a discussion on the research done in the area of chess openings. Specifically, the popularity of chess openings. It turns out the popularity of opening moves does follow Zipf's Law with a distribution that seems to mirror the distribution of such diverse subjects such as website popularity, city populations and word usage.
The article in the link is only a review of the work btw. Click through to the pdf document for the actual study.