The Sports Blog Index is Sports Media Challenge's ranking of the top sports blogs on the internet. These sites are not necessarily the most visited sites on the internet, though traffic is a factor. Each SBI blog is rated on three main criteria: Influence, Community and Relevance. It is important to note that the Index is not a completely objective or subjective measurement. Each blog is ranked on a variety of quantitative measurements before Sports Media Challenge analysts adjust for qualitative factors.

An overview of the three main criteria:

Influence
The influence is a measure of a blog's overall impact within the blogosphere. This is primarily based on a blog's incoming and outgoing links. In particular, the SBI looks to measure links on the main area of a page as opposed to links within a page's blogroll or sidebar. While blogrolls are useful for a new site to gain exposure or for an established site to point out blogs that are notable, they are not a particularly good measure of what blogs are truly producing "linkable" content.

Community
A blog's community is a large part of the SBI measurement. While page views and visits are a good indicator of the size of the community, neither is a good indicator of how active a community is. The community measurement takes into account web traffic as well as comments, unique commentators, and response rates along with several other factors.

Relevance
The final criterion is primarily an analysis of the blog's actual relevance. The open ended nature of blogs provides for great content, but often the subject matter on any one blog my range beyond its stated or implicit subject matter. In addition to a check of relevant content, this includes a check of the ensuing discussion. While a community may be active, if the discussions are continually off topic, then it is reflected in the ranking.