Personnel report: Cardinals evolving on offense

Posted by ESPN.com's Mike Sando

PHOENIX -- The Cardinals did something Saturday they hadn't done all season. They did something I hadn't seen from an NFL team in the more than 5,400 offensive plays I've charted over the last few seasons.

What they did during their 30-24 victory over the Falcons -- use two tight ends and three wide receivers in the same personnel group -- might not have much staying power. In theory, the grouping should afford greater perimeter pass protection while still allowing Kurt Warner to choose from three wide receivers. In reality, the Cardinals used the combination three times, all on third down, and the results were ugly: Two incomplete passes and an interception.

The personnel-tracking system I've developed doesn't even account for that personnel grouping. Instead of changing my system to accommodate a personnel combination we might never see again, I eliminated those plays from consideration in the usual Excel file breaking down offensive personnel use from multiple angles. The plays appear in the chart topping this blog entry.

The unexpected emergence of this odd personnel combination plays into a broader theme for the Cardinals. This offense is evolving. The approach Arizona used against the Falcons marked a departure from the way we've seen the Cardinals operate most of the season.

We saw far fewer four-receiver groupings and more two-receiver groupings, with nine running plays from the I-formation and offset-I formation. Two factors are influencing the shift. One, the Cardinals are looking for ways to get the ground game going with Edgerrin James at halfback. Two, the Cardinals have fewer options at receiver when Anquan Boldin isn't healthy.

Boldin's injury situation -- he entered Saturday with a shoulder injury and emerged with a hamstring injury -- could persuade the Cardinals to remain more of a two- and three-receiver team. That style arguably gives the Cardinals their best chance in the playoffs because it facilitates the running game and, by extension, balance.

Arizona used its one-back, three-receiver, one-tight end grouping to great effect against Carolina in Week 8. I'm thinking we'll see that group quite a bit in the playoff rematch.