Several people shouldered blame following the 49ers’ loss to the Rams this Sunday. David Akers, Colin Kaepernick and Greg Roman headlined the list of scapegoats, and to a certain extent they deserved it. Although they all played their part in keeping the 49ers from securing a win, the offensive line was the biggest reason that the team struggled.

That’s right — the same squad that made Kaepernick look so good against the Bears kept him running for his life on Sunday, and that wasn’t even their biggest weakness. Their run blocking performance was probably their worst this year, and holding penalties stalled even more possessions that could have resulted in scores.

Let’s take a look at three different drives that could have been, but weren’t, thanks to poor line play.

Drive #3

After going three-and-out on their first possession and scoring on the second, the 49ers seemed to be rolling yet again. The Rams punted to San Francisco’s 40-yard line and the 49ers took over, moving the ball quickly. After a short Brandon Jacobs run, Kaepernick completed a 16-yard pass to Randy Moss. Then Frank Gore got the call on a run between left guard and tackle — it should have been a gain of 16 yards, but Joe Staley turned it into a 10-yard loss instead.

Staley has Michael Brockers well handled when Gore takes the handoff. He holds the block through Gore’s cut and is still legally holding off the defensive tackle when his running back gets past them.

Brockers reaches for Gore as he passes, but he never would have gotten a hand on him. This was where Staley made his mistake, tackling Brockers after Gore reaches the second level.

There it is. The call wiped out a 16-yard run, back up the offense to their own 42-yard line, and the 49ers punted three plays later.

Drive #4

I don’t mean to pick on Staley, but it got worse for him on the next drive. The 49ers got two quick first downs on passes to Delanie Walker and Michael Crabtree before they turned to the run to try and move the chains. The first run for Gore netted two yards, but the second one was the real drive killer.

Initially, Staley is supposed to take on William (Willie Mayes?) Hayes, but safety Craig Dahl runs up on a blitz when the ball is snapped. Staley chips Hayes quickly and then lets him go to block Dahl. Meanwhile, Gore takes the handoff and heads towards right tackle.

Mike Iupati pulls and Bruce Miller follows him, so no one is accounting for Hayes. Dahl may have gotten to Gore in the backfield, but the man with the shortest route to the running back is Hayes. Staley should have recognized that.

Hayes catches Gore for a three-yard loss. In the interim, Staley couldn’t hold his block on Dahl, so he watches as both of his assignments run free in the backfield. The next play was an incomplete pass and the 49ers were forced to punt from midfield yet again.

Kaepernick’s safety

This drive — which started at the 49ers’ 4-yard line — may not have gone anywhere, but at least their backs weren’t against the wall anymore after a 17-yard pass to Mario Manningham. Then the Rams dialed up an exotic blitz that center Jonathan Goodwin couldn’t handle.

The Rams bring both Janoris Jenkins and James Laurinaitis on a blitz. Gore picks up Jenkins, but Goodwin focuses on Kendall Langford and does nothing to account for Laurinaitis, who supplies the initial pressure. This causes Kaepernick to scramble right into Jenkins’s pressure.

Langford gets past Goodwin and Laurinaitis comes through the line untouched. Had Goodwin stopped at least one of them (preferably Langford, which would have given his quarterback an escape valve to the left), Kaepernick would have been able to step up in the pocket, or at least escape the pressure by running forward. Instead it resulted in a safety — two points that were integral in the Rams tying the game, and later, winning it.

These are just a few examples of how the offensive line hindered drives. According to Pro Football Focus, Kaepernick had an average time to throw of 2.94 seconds, the lowest of all his starts. The linemen were called for three different holding penalties, all on separate drives that stalled as a result. Finally, Frank Gore averaged a season low 2.52 YPC, which had more to do with his blocking than his running. PFF gave run blocking scores of -.4, .1 and .7 to Goodwin, Staley and Iupati respectively — far below their season averages. It all adds up to a bad offensive day for the red and gold, and it’s in stark contrast to the 49ers’ performances against the Bears and Saints — proof that when the blocking goes, so goes the scoring.