The Ballbug Leaderboard lists the sources most frequently posted to Ballbug.

This particular version corresponds to the 30-day period ending May 20, 2013.

Sources are ranked by Presence, the percentage of headline space a source occupies over the 30-day period. "Discussion" links are not taken in to consideration here — only full headlines are counted.

An OPML file containing this list can be found here.

For more information, see this announcement