It is easy to conflate Which team is number one? with Which team wins today? The former is decided over the course of a regular season and is primarily driven by skill (talent) but the latter changes on a daily basis and when there are two roughly equal opponents it is principally governed by luck!
With respect to being number one, the definitive review of the field is provided by Langville and Meyer (2012) in Who's #1?: The Science of Rating and Ranking. And, in terms of estimating true talent levels, Adam Dorhauer delivers two excellent articles worthy of publication, Elo vs. Regression to the Mean: A Theoretical Comparison and Regression with Changing Talent Levels: The Effects of Variance.
With respect to being number one, the definitive review of the field is provided by Langville and Meyer (2012) in Who's #1?: The Science of Rating and Ranking. And, in terms of estimating true talent levels, Adam Dorhauer delivers two excellent articles worthy of publication, Elo vs. Regression to the Mean: A Theoretical Comparison and Regression with Changing Talent Levels: The Effects of Variance.