Breaking down the 49ers' offensive personnel

The NFL is a one-back, three-wide receiver league. That is, unless your team happens to be coached by Jim Harbaugh.

On Thursday, Football Outsiders released their offensive personnel data for the 2013 season and, as has become the norm, the San Francisco 49ers stood out from the rest of the league in regards to which five skill position players they chose to send on the field. Here is a look at the 49ers' offensive personnel usage (data not in linked article above comes from previous Football Outsiders Almanacs) since Harbaugh took over as head coach:

In a copycat league, the 49ers are choosing to go the other way. The NFL's usage of 11 personnel (one running back, one tight end, three wide receivers) has increased in each of the last four seasons according to FO's data, reaching a peak of 51.2 percent in 2013. San Francisco's use of 11 personnel has remained flat since Harbaugh took over, sticking between 20 and 22 percent in each of his three seasons as the 49ers' head coach. Another one-back grouping, 12 personnel (one running back, two tight ends, two wide receivers), has been the second most popular personnel grouping among NFL teams, hovering consistently around 20 percent for the past several seasons. In 2011, 12 personnel was actually the 49ers' preferred personnel group (27 percent), but Harbaugh has used it less frequently in each season since with its usage dropping all the way down to 15 percent in 2013.

There are several reasons to explain this phenomenon. The easiest explanation is also the most practical; the 49ers have been one of the league's only teams better suited to put fewer wide receivers on the field. It's been rare that San Francisco has had more than one wide receiver on the roster worth giving significant playing time to. That one receiver, of course, has been Michael Crabtree. When the 49ers finally added a capable second option at the position last season by trading for Anquan Boldin, San Francisco was robbed of the opportunity to have Crabtree and Boldin on the field at the same time for the majority of the season after Crabtree went down with an Achilles injury. This left them with just one reliable wide out once again. Getting their five best skill position players on the field meant more Delanie Walker, Bruce Miller and Vance McDonald and less Kyle Williams, Ted Ginn and Mario Manningham.

The data backs up this idea as well. While FO is holding their personnel-specific DVOA numbers for the 2013 season until the release of the upcoming Football Outsiders Almanac, we do have that data for 2012 and 2011. In each of those years, the 49ers recorded a negative DVOA when using 11 personnel, meaning they were worse than average with three wide receivers on the field. In 2012, their negative-12.5 percent DVOA in 11 personnel was by far the worst mark of their four most heavily used personnel groupings.

San Francisco's success with heavier personnel groupings has been a bit mixed. In 2011, 22 personnel (two running backs, two tight ends, one wide receiver) was their worst performing personnel group with a negative-16.9 percent DVOA. That number jumped considerably in 2012 as the 49ers finished the season with a 23.4 percent DVOA when using 22 personnel. Part of that jump is undoubtedly due to the fact that San Francisco was simply much better on offense as a whole during that season, climbing the ladder from the 18th-best offense in 2011 to the fifth-best in 2012. I would hypothesize that San Francisco's 22 personnel DVOA for 2013 was somewhere in the middle of their output in the two preceding seasons.

In what can only be described as a undeterrable attempt to make 1970s-style football relevant again, the 49ers continue to use 22 personnel more than any other team in the league by a considerable margin. They've gone to this grouping more and more with each passing season, lining up with two backs and two tight ends on a league-high 26 percent of snaps in 2013. As Aaron Schatz points out in the FO article, this was twice as often as the next closest team, the Minnesota Vikings. The Vikings trotted out 22 personnel 13 percent of the time, no other offense used that grouping on more than 10 percent of their offensive snaps.

I know many have not been happy with how Harbaugh and offensive coordinator Greg Roman have chosen to run the offense at times. Strictly in terms of their personnel choices, it's difficult to dispute that their plan of attack hasn't been the correct one considering the construction of the roster. At the very least, it has been a unique approach for opposing defenses to prepare for. The 49ers have used four different personnel groupings at least 15 percent of the time in each of the past three seasons and they've been the NFL's only team to do so for at least the last two.

The important question going forward is whether the 49ers preferred personnel groupings will change as the roster does. By adding Stevie Johnson and Bruce Ellington into the mix, the 49ers will field their most talented wide receiver corps in quite some time, assuming they can all manage to stay healthy. I've heard many people imply, or say outright, that Harbaugh will continue to send out heavy personnel groupings and pound the rock regardless of circumstance. While I certainly do not expect the 49ers to ever resemble a team quarterbacked by Peyton Manning as long as Harbaugh is in charge, I do think Harbaugh has shown that he is going to put the best players on the field. If the roster construction changes in a way that dictates more use of three wide receivers on the field, I genuinely believe that's what we'll see happen. Unfortunately, we're going to have to wait just over 100 more days to find out.