I find that most experienced managers have become experts at identifying and gaming flaws in measurement systems. The in and outs of measurement systems have always interested me, both in business and in sports (how about that segue-way?)
Those of you who are baseball fans may be familiar with Bill James. Bill James came to the conclusion that baseball stats really didn't say very much about what went on in a game, and were misleading in evaluating individual performance. He and people like him have asked questions like "is RBI production really a fair measure of individual performance (since it depends on teammates getting on base)" and "why are walks left out of traditional hitting stats". My post is really on football, but if these baseball questions interest you, check out the book Moneyball.
Much like these baseball stat pioneers, there are a number of people trying to rethink football statistics. For example, is total yardage given up a good measure of defensive productivity? Won't a mediocre defense on a team with a great offense that grinds out 8 minute drives sometimes look better on this stat than a good defense on a team with an offense that is always 3 and out? A site called Football Outsiders is one example of the search for better football understanding. If you are numerically inclined, and are tired of the "its all about execution, about taking it one game at a time" football analysis, check these guys out.