SportsMediaWatch.com has a few more PGA Championship ratings for CBS. The 3.9 overnight was down 9% from '11 and 22% from '10 and was the lowest since '08, but it did outdraw the Open Championship slightly and Saturday was not horrible.
On Saturday, third round action drew a 2.7 overnight (excludes rainout coverage) — actually up a tick from last year (2.6), but down 13% from 2010 (3.1).