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Statistical Review of the 2009 49ers: VIII. Offensive Line

AUTHOR'S NOTE: If you're not already using the wide view of the site, switch to it after the jump because one of the tables is a little too wide for narrow view.

Welcome back for the 8th installment of my 2009 Niner stat review. If you missed Parts 1-7, you can read them here, here, here, here, here, here, and here.

Today in Part 8, I'll take a look at the OL. For some of us on NN - including me - the OL is where the 49ers' perennial problems on OFF begin. The theory goes that, no matter how much skill position talent they have, a team can't run the ball effectively if their OL can't open holes for RBs; nor can they pass the ball effectively if their OL can't protect the QB. In the context of the 49ers, this means that they can give the ball to Frank Gore 40 times a game, but it's pointless if he's constantly getting hit behind the line. Similarly, they can use as many top-10 picks as they want on pass-catchers like Vernon Davis and Michael Crabtree, but it's pointless if their QB is constantly getting hit, hurried, and/or sacked.

In this context, it's curious that the Niners haven't developed a better OL over the past 5 seasons. As Matt Maiocco has pointed out, recent 49er drafts have resulted in an un-Walsh-like number of OLs picked in the first 3 rounds. Here's a crazy stat for you: From 1979 to 2001 - that's 23 drafts, by the way - the Walsh-Policy-Walsh-led Niners took exactly 7 OLs in Rounds 1 to 3. Over the past 8 drafts, the Donahue-Nolan-McCloughan-led Niners have already taken 6. Therefore, the post-Walsh Niner GMs have certainly been trying to improve the OL much more than did their predecessors. Given Walsh's success with unheralded OLs, why the seeming philosophical change towards drafting heralded OLs early and often?

After the jump, I attempt to answer the question, and then go over this season's OL stats...

The obvious answer, of course, is the difference in OL characteristics sought by the various regimes. Under Walsh-Policy-Walsh, Niner OLs were supposed to be small, athletic, and versatile for the purposes of the WCO. In contrast, recent regimes have preferred big, mountain-sized, maulers for the purposes of overwhelming opponents with brute strength in the running game. Why this difference translates to the draft - at least in my mind - is that, as McCloughan has repeated over and over again, size is a valuable commodity. Therefore, whereas Walsh could sit back and wait for his miniature OLs because everyone else in the NFL was taking the (lowercase g) giants, Donahue-Nolan-McCloughan have been forced to take OLs early in the draft because, if they don't, all the best sasquatches will be gone; at least in theory. To boot, the differences in winning percentages between the two types of regimes only served to exacerbate the difference in OL draft trends, with the higher picks earned by below-.500 Donahue-Nolan-McCloughan teams being ripe for a we're-never-going-to-get-a-guy-this-big-and-talented-later-on reach.

The less-conspicuous answer is McCloughan himself; well, at least his pedigree. Specifically, his entire pre-49er career was spent apprenticing under Ted Thompson; first as a scout for the Packers from 1994-1998, and then as the Director of College Scouting for the Seahawks from 1999-2004. In that 11-draft span, McCloughan's former teams selected 8 OLs in the first 3 rounds; a 73% rate that's comparable to the Niners' 80% rate since 2005.

So, the available evidence suggests that there's been a structural shift in OL drafting philosophy because of a concomitant shift in desired OL characteristics, as well as the hiring of a personnel director who trained in a different paradigm. How's that worked for them?

Well, first let's look at whether their stated draft-big-OLs-for-run-blocking philosophy has actually improved the 49ers' run-blocking and run OFF efficiency rankings:


Beginning in 2005, the Niners' run blocking and run OFF have, in fact, improved. In addition, changes in run-blocking have paralleled changes in run OFF efficiency as we'd expect. The seeming divergence that occurred in 2008 is interesting, but may just be a random, one-off event. So, taken together, it does appear that the Niners' current OL-drafting philosophy has helped the run OFF, which was its stated purpose. But what has it done to pass protection?

Here's the same type of graph as above, except I've substituted ASR and Pass OFF DVOA rankings for ALY and Run OFF DVOA rankings:


As is evident, the 49ers' pass-blocking has nosedived ever since the front office switched to the current philosophy of drafting irresistible run-blocking forces along the OL. Furthermore, this general trend is supported when you look at the specific OL they've drafted. Namely, Ts are more vital to pass protection than Gs and Cs, yet the Niners have selected only 2 Ts among their 6 OL picks in the first 3 rounds since 2002, both of which were actually RTs better known for their run blocking than their pass protection (Kwame Harris and Joe Staley). Not to mention that the tackles of note that SF has signed through free agency (Barry Sims and Tony Pashos) were, again, RTs from strong running teams. So, the point here is that the Niners' OL philosophy since 2002 has had the intended effect of improved run-blocking, but has also had the unintended effect of incompetent pass-blocking.

The reason I bring all of this up, of course, is to beat the dead horse one more time about the Niners needing to improve their pass OFF efficiency if they have aspirations of playoff participation. As the graph above shows, the Niners' Pass OFF DVOA ranking has nosedived right alongside its ASR ranking. The correlation between these two sets of rankings since 2002 is 0.959; meaning that, if you know one for a given season, you can easily guess the other with amazing accuracy. To see this phenomenon in all its glory, just check out how close the two data points are for each season. The reason you see only 1 data point for 2007 is because they were ranked 32nd in both ASR and Pass OFF DVOA.

I hope I've made my point clear. Previous parts of this series have shown that the 49ers must improve their pass OFF in order to be a serious playoff contender. Looking at the OL, it's obvious that said pass OFF improvement depends almost entirely on an improvement in pass protection. If their 2010 OL once again resembles the token-accepting machines in NYC subway terminals rather than the stone monument in Wiltshire, England, then we shouldn't be too optimistic about their playoff chances.

OK. Rant done. On to the OL's 2009 stats.


First, here's just a bit of housekeeping. Football Outsiders (FO) recently revamped their OL yardage stats in 2 ways:

  1. Their stat formerly known as 10+ Yards, which measured yards per RB carry after 10 yards beyond the line of scrimmage, is now called "Open Field Yards."
  2. They added a stat called "2nd Level Yards," which measures yards per RB carry between 5 and 10 yards beyond the line of scrimmage.

Therefore, I'll be including both of these stats in this post and future OL posts, as well as 1st Level Yds, which you can just calculate via simple subtraction.

Below are FO's yardage stats for the 49ers' OL in 2009, along with those of the average playoff OL and the Super Bowl champs' OL (Top-8 performance in bold; Bottom-8 performance in italics):






1st Level


2nd Level


Open Field



































Based on their 2009 ALY, it seems that the aforementioned divergence between run-blocking and run OFF efficiency does indicate an increase in the amount of non-dependency between the two. Indeed, whereas the Niners' OL was far better at run blocking in 2008 than their Run OFF DVOA otherwise indicated (#7 and #24, respectively), the opposite was true in 2009 (#32 and #14, respectively). I have no idea what the reason for this phenomenon is, but what I do know is that it hasn't occurred vis-à-vis their pass protection, which continues to track alongside their Pass OFF DVOA. More on that shortly.

One thing the yardage stats above clearly show is that the pattern of 49ers' OL stats is the opposite of successful teams in 2009. Specifically, the playoff teams were ranked higher in ALY, 1st Level Yards, and 2nd Level Yards than they were in Open Field Yards, while the Niners were ranked higher in Open Field Yards than in the other categories. What does this mean? Before answering this, first let's add OL efficiency stats to the equation:


Power Success Rate


Stuff Rate

















What we see here is that playoff teams are especially good at preventing stuffs, which are RB carries stopped for 0 or negative yardage. The Niners, in contrast, allowed the highest percentage of stuffs in the NFL. This fits neatly with the yardage patterns I described a second ago, and suggests that success in the running game is predicated on having an OL that wins its battles at the 1st Level (0-5 yards beyond the line). Therefore, having a low frequency of 0- and negative-yard runs is far less important for team success than having a high frequency of 40-yard runs. The Niners of 2009 fit the latter description while playoff teams fit the former.


Based on the above, it stands to reason that, if the 49ers' OL prevents more stuffs, then the overall run OFF will improve considerably. To me, the fact that they're so bad at it indicates one of two things. Either the OL lacks strength - despite having been drafted/signed specifically because of their size - or the opposing DEF was able to nullify Niner strength advantages by knowing their directional run tendencies. Far be it from a puny stats geek like me to question someone's strength, so it's fortunate that the stats seem to support a tendency-based explanation.

Here's the now-familiar directional OL chart for 2009:


First, check out those attempt percentages! As Matt Barrows recently discussed (using FO stats no less!), the Niners' opponents must know that they run the ball up the middle 71% of the time, and that obvious tendency must be one reason for the OL's dead-last Stuff Rate. I mean, some of you may believe that stats don't matter, but rest assured that every NFL team includes stats like these as part of their game-related scouting.

What's odd, though, is that, in addition to opponent awareness, NFL teams also engage in a good bit of self-awareness, i.e., they know their own tendencies as much as (or more) intimately than those of their opponents. With an up-the-middle percentage as high as the 49ers', they don't seem to be doing much self-scouting. I mean, it's not like it was up around 90% at midseason, but then fell dramatically once Jimmy Raye and company figured out their lack of variety. On the contrary, the Niners' up-the-middle percentage basically remained the same the entire season. To me, that's yet another testament to Frank Gore. It's incomprehensible how he gained over 1,000 yards with the opposing DEF knowing what was coming.

One additional point I'll make about the 49ers' run tendencies is that, in general, the OL was more successful at blocking in directions to which they ran least frequently (i.e., LE & RE) than at blocking in directions to which they ran most frequently (LT, C/G, RT). Low and behold, the run OFF gained descent yardage when they ran to the outside. Just like in poker, football teams seem to benefit from playing contrary to their own tendencies from time to time. The Niners' OL in 2009 was a perfect example.


Finally, as promised, here's a table showing the Niner OL's pass-protection stats, along with those of the average playoff OL and the Super Bowl champs' OL:




Sack Rate

















Once again, the 49ers' OL was in the bottom quartile of NFL with respect to pass protection. That makes 3 years straight, and 4 out of the last 5. So, in case you're wondering, the trend I showed earlier continues: SF's Pass OFF DVOA goes as its OL's ASR goes. This season, their ASR ranked 26th, and their Pass OFF DVOA ranked 22nd.

Nevertheless, it should be said that these stats represented a slight improvement over 2008, a season in which they were 31st in ASR and 26th in Pass OFF DVOA. Given Mike Martz's penchant for calling 7-step drops, a pass-protection improvement under Raye was probably to be expected.

In comparison to the average playoff team, the Niners' OL once again didn't measure up. Insert beating of pass OFF dead horse here.


Given that this is the last of the OFF-related reviews, I'll just quickly recap the general point I've been making thus far in the series. Namely, it's the pass OFF, stupid! Really, it's as simple as that. The Niners' decline since 2002 has coincided with declines in their ability to move the ball through the air, which has in turn coincided with a decline in their ability to protect the passer. Furthermore, based on the individual stats I've presented, it seems like - for the first time in forever - there isn't a pressing need for skill position talent. Rather, the stats suggest Vernon Davis are sure things, Michael Crabtree is a soon-to-be sure thing; and Alex Smith and Josh Morgan stand to gain considerably from this offseason's relative stability vis-à-vis their OC.

As far as the run OFF goes, the stats suggest that Frank Gore is a sure thing, and that the OL's run-blocking ineptitude in 2009 had more to do with a lack of self-awareness on the part of their play-caller than anything else. Indeed, the run-blocking trend since McCloughan arrived in 2005 was reflective of an improving unit, not a worst-in-the-NFL one.

Therefore, based on the stats I've presented in Part 8 of the season review, here are the things the Niners need to do on the OL in order to seriously contend in 2010:

  1. Decrease their up-the-middle run frequency by 15-20% so that they regain the strength advantage that's a fundamental purpose of their OL philosophy
  2. Decrease their ASR by about 3%

*DVOA, DYAR, and EYds statistics used to produce this article were provided by Football Outsiders.