The San Francisco 49ers have not been good at preventing sacks the last decade

This is probably not the most shocking revelation, but it turns out the San Francisco 49ers have not been particularly good at preventing sacks over the last decade. In case this revelation has left you speechless, take a look at the quick breakdown Football Perspective put together.

Chase Stuart wrote about which offenses have been best and worst at preventing sacks. He took a look at the differential of expected sacks versus actual sacks for the 2014 season. Expected sacks look at the total sacks a quarterback should take given the league average sack rate and number of drop-backs. He compares those numbers and ranks teams based on the differential. Last season, the Denver Broncos led the way by a sizable margin. This is not surprising given that Peyton Manning drops back a lot without giving up many sacks. The 49ers on the other hand ranked 30th, with 52 sacks but only 34.2 expected sacks (-17.8 differential). They were just ahead of Washington (-19.6 differential), and well ahead of the last place Jacksonville Jaguars (-31.1 differential).

Chase then went into detail on how teams have performed over the last decade in preventing sacks. It is hard to compare a lot of teams over a decade given the roster turnover, but he provides a helpful heat map for each year. The darker the red, the worse an offense was. The darker the blue, the better the offense was. If you look at the 49ers, there is a whole lot of red.

The first table lists each team's performance in sack differential dating back to 2002. The second table shows the cumulative sack differential dating back to 2002. The third table shows each team's ranking in sacks allowed again dating back to 2002.

The one consistent thing we see is the 49ers offense has struggled mightily when it comes to keeping the quarterback on his feet. They did fine in Jeff Garcia's final two years, but things quickly went in the tank after that. Of course, early on that coincided with the 49ers descent into failure. Although the team did build up the run game behind Frank Gore, the pass protection was inconsistent. Alex Smith frequently took sacks rather than risk a bad throw, and we have seen Kap have his own issues with sacks. There is no single answer, but rather a mix of blame to spread around between quarterback, line and more.

This year, the 49ers will see some changes on the offensive line. Brandon Thomas is likely going to move into the starting lineup at guard, and the 49ers will try and settle on a single center for the season. Kap has been working on his mechanics and film study. The mechanics will hopefully mean improved accuracy, but maybe it helps him find his targets quickly and get the pass away before the pass rush hits. And of course, the team added Torrey Smith in with Anquan Boldin, and we hopefully see improvement from Vernon Davis and Vance McDonald. Getting more consistency from the receiving weapons adds potentially adds to the improvement.

It remains to be seen what we'll see this fall, but improvement in preventing sacks is critical to seeing this offense gain some measure of consistency. We've seen a mix of highs and lows over the years, and it would be nice to see some kind of consistency.