Breakdown: 49ers' personnel in Week 4

Posted by ESPN.com's Mike Sando

Here's what jumped out at me after breaking down the 49ers' offensive personnel use against the Saints in Week 4: The team struggled badly with one running back, three wide receivers and one tight end on the field together.

Overall, the 49ers had 11 plays longer than 10 yards against the Saints. A week earlier, the 49ers had a dozen such plays against the Lions. And yet the results were dramatically different on the scoreboard. The two end-zone interceptions thrown by J.T. O'Sullivan were part of that. The 49ers also had a hard time against Saints quarterback Drew Brees.

But let's get back to the personnel analysis. I looked at the 49ers' first 58 plays against the Saints, excluding the final desperate series when the outcome was decided. The 49ers ran only 13 plays -- 26 percent of snaps -- with two tight ends on the field.

This marked a departure from the approach against Detroit. Twenty of the 60 snaps I analyzed against the Lions featured two tight ends. A dozen of those 20 snaps featured Frank Gore as the lone running back; the 49ers averaged 6.8 yards on eight carries and 14.7 yards on three pass attempts from that grouping (the 12th play, a quarterback scramble, was tossed out).

We can reasonably conclude that falling behind against the Saints took the 49ers out of their double-tight packages. They went with three receivers on 23 snaps (39.7 percent) and four receivers on 15 snaps (25.9 percent). That means the 49ers used three or more receivers on 65.5 percent of snaps, up from 46.7 percent on those 60 snaps against the Lions.

I think the 49ers are at their best with Vernon Davis and Delanie Walker on the field together with Frank Gore and two receivers. Davis and Walker run well enough to factor into the passing game, yet the nature of the position also allows them to block for the run or protect the passer. Tim Ryan, the analyst for Fox, said on the air he expected Martz to use this grouping -- known as "Dice" -- more frequently.

Martz rolled with the "Dice" grouping only seven times against the Saints. This featured one play with an empty backfield. On the other six, the 49ers averaged 6.0 yards on two rushes and 14.7 yards on three pass attempts (not counting a sack). O'Sullivan also threw one of his interceptions from this grouping, but that pass was tipped at the line (in my view). Otherwise the 49ers might have had a touchdown on the play.

By contrast, let's take a look at the one-back, three-receiver, one-tight end grouping. Counting sacks and incomplete passes, the 49ers averaged 2.6 yards on 17 pass plays from this grouping. That included 1.4 yards on eight first-down plays (with two sacks and an interception); 2.0 yards on five second-down plays (with two sacks); and 6.0 yards on four third-down plays (three incomplete passes and a 24-yarder to Gore).

I'll make available an Excel file with two sheets: one sheet breaks down the 49ers' production by personnel group; the other sheet features a sortable play-by-play.