So, just what is passer rating?

Roger, from Southgate, Ky., wrote today and asked what passer rating is. The best explanation I can offer is from a story I wrote that was published Oct. 20, 2005 in The Enquirer. It ran in advance of the first Bengals-Steelers game:

The two quarterbacks with the NFL's best passer ratings, Ben Roethlisberger and Carson Palmer, will face off Sunday at Paul Brown Stadium.

The Bengals' Palmer will try to set an NFL record, which he now shares with Indianapolis' Peyton Manning, with his 10th consecutive game of a 100.0-plus passer rating.The Steelers' Roethlisberger leads the NFL with a 123.8 rating.

Palmer is second at 113.6.

The game will be just the second time since 1990 that two quarterbacks with ratings of 113 or more will start in the same game. The only other time was Nov. 8, 2004, when Manning (117.4) faced Minnesota's Daunte Culpepper (114.2).

Passer rating is a measure that uses percentage of completions per pass attempt, average yards gained per attempt, percentage of touchdown passes per attempt and percentage of interceptions per attempt. The NFL emphasizes that the rating measures passers, not quarterbacks, and does not reflect factors such as leadership.

The league considers these standards as exceptional: 70 percent completions, 10 percent in touchdowns and 1.5 percent in interceptions and 11 yards average gain per pass play. The highest possible rating is 158.3.

Through six games, Palmer has completed 72.6 percent of his passes, thrown an interception on 1 percent and a touchdown on 6.6 percent of his attempts, and averaged 7.98 yards per pass attempt.

In four games, Roethlisberger has competed 60.5 percent of his passes, thrown no interceptions and a touchdown on 8.1 percent of his attempts, and averaged 10.62 yards per attempt.

The system was adopted by the league in 1973 to provide a means to compare passing performances from one season to the next.