The chart shows Alex Smith's 2010 passing stats on third down when the team used its three-receiver offense (one back, one tight end).
The 49ers, on average, needed an additional 2 yards for a first down when playing the Seahawks in the opener as opposed to playing the Saints on Monday night. Smith faced more favorable distances in Week 2.
A few other observations on these plays:
Smith threw two picks in the Seattle game on these plays. He was targeting Michael Crabtree both times. He did not target Crabtree on any of the corresponding plays against the Saints. By corresponding plays, I mean third-down pass attempts from the three-receiver personnel in question. Does Smith trust Crabtree in those situations?
Frank Gore's running gets some of the credit for the striking disparity. The team also did a better job getting plays to Smith on time (although the play clock nearly expired before Smith found Gore for a 7-yard completion on a third-and-8 play).
Against Seattle, the 49ers failed to convert any of the 11 third-down plays in question. They converted two of four against New Orleans, including one to Gore for a 12-yard touchdown on third-and-7.
Vernon Davis wasn't a big factor in these situations against the Saints, but if you notice the 49ers shifting to 22 personnel (two backs and two tight ends), watch for Smith to target one of the big guys downfield. Smith found tight end Delanie Walker for a 14-yard gain from 22 personnel on third-and-1 against Seattle, the 49ers' only conversion of Week 1. He found Davis for a 15-yard gain from 22 personnel on a third-and-4 play against the Saints. Davis' 73-yard touchdown catch against St. Louis in Week 17 last season was from this personnel on third-and-1.