Pro Football Reference Blog

Note: The initial post was based on an inaccurate query. Our apologies for the mistake. The below numbers are now accurate.

Which quarterback has thrown the most interceptions that have been returned for touchdowns in league history? While we don't have that exact data available, we can do a reasonably job of answering that question based on the tools we do have here at PFR, which include:

• Individual game logs for all players, showing all interceptions thrown, dating back to 1960

• Individual season logs for all players, showing all interceptions thrown, dating back to 1920

• Scoring logs for all scores, showing all interceptions returned for a touchdown, dating back to 1940

For any game from 1960 to 2009 (2010 data not included), we can do a very good job approximating who threw the pick-six. For the vast majority of teams, only one player (at most) will throw an interception in any given game. Fifty years from now, if you look at the box score from this past Monday night, you will be able to know for sure that Brett Favre threw the interception that Dwight Lowery returned for a touchdown. The Vikings threw just one interception, and it was by Favre, so Favre must have thrown the pick-six. It doesn't matter if the team has thrown five interceptions, as long as all were thrown by the same guy, such as Keith Null against the Titans last year.

The problem games are the ones where multiple players, usually quarterbacks, threw interceptions. For example, against the Patriots earlier this season, Chad Henne threw three interceptions and Tyler Thigpen threw one. We can check the game log to see that Chung's interception came on a pass from Henne, but we don't have game logs dating back to 1960. The shortcut we'll use? Award Henne 0.75 pick-sixes and Thigpen 0.25; obviously this isn't perfect, but over the course of a player's career, I think this will work well as an approximation.

For games from 1940 to 1960, we'll have to be quite a bit rougher with our approximation. In this 1957 game against the Packers, Jack Christiansen scored on a 29-yard interception return. Whom do we blame on the Packers for that? In 1957, Babe Parilli threw 12 interceptions, Bart Starr threw 10, and Ron Kramer threw 1 for Green Bat; as a result, Christiansen's pick-six gets recorded as 0.52 P-6s for Parilli, 0.43 for Starr and 0.04 for Kramer. That's the best we can do for the pre-1960 games.

Once you go through every game from 1940 and 2009, using the system described above, it's easy to tally a career list. So which quarterback has thrown the most approximate pick-sixes in league history? Prepared to be floored:

We can get a little more precise when it comes to Favre. In two of his games, he was credited with two-thirds of an interception, which explains why he's listed with 32-and-a-third interceptions returned for touchdowns in his career. In '08, against the Chargers, Favre threw two interceptions and Kellen Clemens threw one. A quick check at the play log confirms that it was one of Favre's interceptions that was returned for a touchdown. The other interception in question? It famously came on Favre's first pass, as detailed by Peter King here. So we can verify that Favre threw 33 interceptions from 1991 to 2009 that were returned for scores, and Lowery's return was the 34th overall and his 30th in regular season play.

As for Marino, we can do a similar analysis. He has only one interception in question, which came on a game played on October 2nd, 1983. Thanks to the PFR commenters, we've learned that Marino was the responsible party for that interception, and thus he ended his career with 30 interceptions returned for touchdowns, with one of those coming during the post-season.

That means Lowery's pick-six this past week was historic: it was Favre's 30th such interception in regular season history, breaking the tie he held with Marino. Thanks to three pick-sixes against the Rams in 2001, Favre already held the record for most career pick-sixes thrown, regular and post-season combined.