Before diving in, I just want to wish everyone a nice holiday week, and safe travels to all those doing so.
NFL 2023 - Offensive Line Rankings
If you are interested in the Math & Methodology just keep reading, or for even more: NFL 2023 - Comparative Offensive Line Ratings
If you are math adverse and just want to read the team offensive line capsules (all the charts and data are still there if you wish to review them): NFL 2023 - Offensive Line Rankings
TLDR: Just look at the last 2 columns on the main chart posted below.
Example Offensive Line Capsule
NY Giants Offensive Line Capsule
The Role & Metrics of the Offensive Line
For the offensive line ratings, we are going to assume that the offensive line’s 4 main objectives are:
- Open holes for the rushing game
- Identify, adjust and negate blitzes
- Protect the quarterback for a reasonable amount of time
- Win & hold blocks as a unit
In addition, like any other player or unit on the field, they should accomplish this without drawing fouls. Since this is basically a given for all units/players, I won’t list it as a main objective, but offensive lines will be scored on their ability to avoid costly penalties.
The List of Offensive Line Metrics
- Rushing Yards Before Contact x 2
- Blitz %
- Pressure %
- Blitz Deflection %
- Average Pocket Time
- Sack %
- Estimated Penalty Yards
- Overall Block Win%
Let’s look at each objective and identify the metric(s) used to measure the line’s effectiveness.
Opening Holes For The Rushing Game
Clearly one of the offensive line’s main tasks is to run block effectively. An offensive line that cannot run block and create opportunities for ball carriers is going to find itself forced into a lot of predictable pass block situations. Without the threat of an effective running game, defensive players can sit on pass routes and pass rushers can pin their ears back.
The metric to be used to measure run block effectiveness is Rushing Yards Before Contact(YBC), and this will be the only rushing metric used… While the ball carrier’s ability is certainly a part of the metric, the size of the hole, or the time until the first defender can make contact with a ball carrier, is primarily a result of blocking. And while wide receivers and tight end blocking is also a factor, we can simply assume that all wr/te blocks are equal(which they surely are not), and assume these blocks are simply an extension of the line blocking(or that the wr/te in the play assume linemen status for the play).
Because the run game can in and of itself win ball games, and an effective run game compliments an effective pass game, the value of this metric will be doubled(the score each line receives for this metric is multiplied by two). Thus the score you see in the Standardized YBC column is the sd value, and the next column shows the YBC score(its SD value * 2).
Pivot tables were needed to sum up totals like every players that has rushed the ball for each time to calculate YBC. You will see more of them below.
Identifying, Adjust To, And Negate Blitzes
This is probably the most difficult and important task assigned to the offensive line. Before providing time for a quarterback to throw, the line must identify the pass rushers, call the line protection, and still be aware of any misidentifications or additional blitzers not accounted for pre-snap. If any of this goes wrong without a blitz, it can lead to a negative play. When it goes wrong with a blitz, the potential for disasterous outcomes rises significantly.
We are going to assign three metrics to measuring this task:
Blitz % - An offensive line that faces a high amount of blitzing will score more higher in this metric. The purpose of this metric is to measure the amount of blitzes the line has had to face while producing the stats it has. It should be clear that a line facing 30% blitz % who gave up just 5 sacks, is probably more effective than a line who faced a 15% blitz % and gave up 5 sacks. Either the blitz pickup of the latter line is not good OR they are getting beat without a blitz.
Pressure % - Pressure % is simply the amount of hurries, knockdowns and sacks as a cumulative total, changed into a percentage by dividing that sum by the amount of pass attempts, scrambles & sacks. It assigns equal weight to a knockdown, a hurry and a sack even though they each have different Expected Point values, and affects on down/distance/outcome.
For measuring purposes, offensive lines that allow the least amount of pressure will score highest.
Blitz Deflection % - This is a metric you have never heard of because I just made it up. I am defining Blitz Deflection % as [1 - (Pressure % / Blitz %)]. Let’s look at a simple example of what it is and why it may be a valuable metric.
Let’s assume a line has faced a Blitz % of 25%. Let’s also assume, that every blitz leads directly to pressure. Thus a Blitz % of 25% should lead to a Pressure % of 25%. Essentially, blitzes always work. Thus if a team faces 25% Blitzes, then the average line would allow 25% pressure.
A line that could keep pressure % BELOW Blitz % would be doing a better job than a line who’s Pressure % was higher than their Blitz %. If this happens the line must be giving up pressure outside the Blitz and negating little to none of the blitzes sent.
Looking at the chart, Baltimore’s offensive line has faced the blitz on 30.68% of designed passing plays. Their pressure % is a mere 14.49%. While this cannot show the exact breakdown of how often Baltimore’s offensive line picked up the blitz and how many time they allowed pressure without a blitz, it should be obvious that line is picking up blitzes.
The ratio [1 - (14.49% / 30.68%)] = 52.78%. Thus Baltimore’s offensive line is deflecting 52.78% of blitzes.
Conversely, let’s take a look at Pittsburgh’s offensive line in this metric. The Steelers Offensive line faces a blitz 18.08% of the time(by far the lowest % in the league, Cincinnati is second least blitzed at 21.61%). However the Steeler offensive line allows a pressure % of 25.32%.
The ratio [1-(25.32 / 18.08%)] = -40.35%. The Steeler’s line is not deflecting any blitzes and giving up pressure outside of being blitzed.
Just remember Blitz Deflection is not measuring the actual amount of blitz pickups, but the theoretical amount a line is negating blitzes.
Protect the Quarterback for a Reasonable Amount of Time
Regardless as to whether the blitz pickup has been identified and executed properly, the offensive line is still tasked with giving the quarterback enough time to go through his reads and complete the passing motion. It would be great if the qb is still standing and in the pocket when this is completed, but sometimes things go wrong and quarterbacks get sacked.
The two metrics being used in this portion of the offensive line ratings are fairly straightforward.
Average Time in The Pocket - The amount of time the quarterback has before contact or being flushed is average time in the pocket. It should follow that allowing more time for the quarterback would be good, and allowing less time bad.
This is a bit of scheming that plays into this as some times have an extremely quick read system that inherently gets the ball out faster than other schemes looking for deeper, or double, routes. But it is a fairly reliable indicator on the ability of the line to pass protect and form a workable qb pocket.
Sack % - Sacks are the worst kind of pressure as they come with loss of down and yardage by the very definition of a sack. This is an inverse metric in that it is better to have a lower sack % than a higher one. Lines that allow a lower % of sack will score well, while porous lines will score poorly.
Minimize Penalties
Another metric in measuring offensive lines will be their ability to avoid getting in their own way. Every penalty on each individual line is collected and the entire line is responsible for the total penalties.
Pivot table summarizing every lineman’s penalties for each team
For estimating penalty yardage, a false start is 5 yards, holding and any other penalty is 10 yards(the other penalties are a mix of 5 yard and 15 yard infractions, thus I decided to use 10 yards as the punishement for each. Offsetting and declined penalties are still counted. Multiplying out the types of penalties and the estimated yardage for each results in an estimated total penalty yardage total for each offensive line. This is also an inverse metric. Lines that have been penalized the most will score poorly, while the mistake free lines will score high.
Winning Blocks - Overall Offensive Line Blocking Win Rate
The final metric is another metric you may not have seen before, Overall Block Win Rate. To calculate this metric, ESPN’s Pass Blocking Win Rate and Rush Blocking Win Rate percentages were used for each team(which just so happened to be published this week).
Then the breakdown between passing and running plays for each team were taken into account. To find the overall block win rate, the pass block win rate was multiplied by the passing play %, and the rush block win rate was multiplied by the rush play %. Turning the resulting metric back into a percentage, leads to overall block win rate.
For example, a team has a pass block win rate of 60% and a rush block win rate of 70%. They pass 60% of the time and run 40% of the time. What is the overall block win %?
Overall Block Win % = [(0.60*60)+(0.70*40)]/100 = 64%
You can see all the data and calculation in the main chart. Perhaps you think everything before this section is nonsense and overall block win rate % is the true measure of offensive lines. In that case, here is the ranking based solely on Overall Block Win Rate %
Overall Block Win Rate when pass/run ratio is factored in.
Final Offensive Line Ratings & Rankings
Summing up the score from the 8 metrics(and doubling the YBC value), we arrive at a final rating for each of the 32 offensive lines. Like any rating system there are sure to be disagreements and niggles in the methodology.
The Offensive Line Ratings see Baltimore, Philadelphia, Miami, & the LA Rams as the having the best offensive lines. It sees Houston, Pittsburgh, Carolina, and the extremely woeful NY Giants as having the worst performing offensive lines thus far in 2023.
How is New England not lower? They have looked incredibly bad all season.