A few observations and related questions.
I haven't read it in a while, but I think the formula used to compare passing vs. rushing efficiency here is Y/C (yards per completion) average gained on offense minus yielded on defense, and YPC (yards per carry) average gained on offense minus yielded on defense.
One conclusion he derives is "rushing hardly matters" in the NFL (a sub-topic title in the article). The formula by which he arrived at this conclusion is a blended or mixed stat that also factors in and accounts for what teams did in pass and run defense. It is easy to see how having a good pass offense and defense could lead to more wins. What is less obvious to me is a situation where a team may have a stellar pass defense, for instance, and average pass offense, but because it yields a large difference, primarily because of the defensive contribution, a conclusion is drawn that they had a good, above average passing attack that correlated to winning. So while a sub-topic title like "rushing hardly matters" would seem to just be speaking to passing only in correlating it with winning, that conclusion is actually speaking about a more complex issue, passing and passing defense (or the rushing data counterparts), and sometimes not equally, but the defense playing a larger role in a given team's success.
Also, what does it mean if we reduce passing success to the one stat of effiency as measured by Y/C average. In other words, if a team threw one pass a game the entire season and ran 98-99% of the time, but completed every pass (16) for 20 yards, that would be interpreted as an efficient passing game, and from this, some might conclude that team had a good passing game.
To use another exaggerated example, if a team drafted an 8'0" 500 lb. QB that just fell down every time and only got 3.4 yards, but ALWAYS got 3.4 yards, they could just go up and down the field every game, he would score 100+ TDs, the team could go 19-0 and win the Super Bowl. But by the narrow efficiency metric used in the article, that would be an example of a "bad" running game (what the rush defense did would also need to be factored in and accounted for with that component).
Some things that may not be factored into a rushing metric this narrow: what if a RB doesn't have a high YPC average (like Lynch and Gore in 2013, they were much better in 2012, probably for several identifiable reasons - SEA had a lot of OL injuries and SF probably faced more defenses stacked to stop Gore with Crabtree missing much of the season last year), but converts in short yardage to sustain drives, can help grind out the clock late and preserve wins, breaks tackles, is physical and punishes DBs, taking its toll on them over the course of the game and is able to punch it into the end zone in crunch time?
Partly what led to thinking about the article in this way is the success of SF recently (three straight conference championship games and one Super Bowl appearance), as well as SEA (two straight playoff appearances and one Super Bowl win), teams I associate with strong running games and stellar defenses. SEA I do think has a very efficient passing offense, Wilson is an outstanding QB. Kaepernick is already an outstanding running QB. Whether by scheme, design and intent, or lack of receiving weapons outside of Crabtree and Davis (Boldin was a nice addition, but didn't overlap with Crabtree much last season due to the ruptured Achilles tendon), he hasn't had as much chance to shine as a passer compared to Wilson (possibly he isn't as good?).
Three seasons for SF and two for SEA isn't a statistically significant sample (this article spans 10 years). Yet, sometimes it seems like the league is cyclical. Maybe defenses, in struggling to keep up with proliferating passing attacks, are using more athletic back seven LBs and DBs that are good in coverage but more vulnerable to a physical, punishing ground game such as that employed by SEA and SF. I think the NFC West had by far the best interdivisional record in the league in 2013, and they were the main reason (of course their defenses probably playing the biggest role of all in their respective recent success.
The article mentions that eight of the last ten Super Bowl winners (from 2003-2012) scored high on their passing efficiency metric. But it is a cliche that great QBs increase a team's chance of getting to and winning Super Bowls. IND, NE and GB are all mentioned. One conclusion I would draw from the fact that those three teams populate the list is it is great to have Peyton Manning, Tom Brady and Aaron Rodgers (why not include Drew Brees while we are at it, he won a Super Bowl).
This begs the question, what if you don't have one of those QBs? Do you still build a passing offense around a QB if you don't have one of the top ones, or maybe shift directions and build a strong running game (or at least a balanced offense).
Even if a team wanted to apply the conclusions and principles of the article (focus more on building an offense based on an efficient passing attack, because "rushing hardly matters), what would be the best way to do that for teams like CLE and OAK this year. For the purposes here, lets observe CLE has an outstanding LT and WR, and OAK has neither. Hypothetically, Joe Thomas and Josh Gordon are both in their prime, and we ignore Gordon's off-field risk. They don't think there is a franchise QB in the draft, or where they are picking, so they elect to fill that positional hole via a free agent vet, or in a future draft. You know in advance Greg Robinson, Jake Matthews and Sammy Watkins will all turn out to be Pro Bowlers and top 5-10 in the league at their respective positions. Would you recommend CLE take the LT or WR? What if you were advising OAK (if different)?
MIN is mentioned in the article as a team that has had success running during the Adrian Peterson era, yet has been up and down with wins. They point to the Vikings best success being with Brett Favre, and seem to conclude from this passing is more important, and rushing hardly matters. What they don't point out is the MIN QB situtaion has been pretty bad outside of Favre in recent years. Perhaps with a QB not as good Favre, but better than they had, they might have enjoyed more success. Than would rushing have mattered, in that case at least?
They do mention SF, and in that case bring up defense. The author seems to make an interpretation, that SF had a good defense before Harbaugh, but only started winning more when they drafted Aldon Smith and acquired Carlos Rogers in free agency, concluding pass defense was the identifiable reason. But is that the only possible reason? This article didn't include the 2013 season, but could part of the 2012 success have to do with the insertion of Kaepernick? Could part of the 2011 (and 2012 and 2013) success have had to do with 2010 rookie first round OL Anthony Davis and Mike Iupati no longer being inexperienced rookies and playing at a higher level, elevating the run game? There could be dozens (hundreds like this for all I know) of variables, it seems a bit simplistic to chalk it up to OLB Smith and CB Rogers?
There is a part of the article I'd like to isolate out and look at separately. It refers to a visual presentation of data that can be found in the article linked in the first post. If I understand it, there is a stronger correlation between improved passing efficiency and ability to predict wins, than with rushing. The impact of rushing efficiency on ability to predict wins appears to be more random. I guess I don't get from this (his method and the conclusions he has drawn) rushing hardly mattered? For the teams that had both high rushing efficiency and won, it would seem rushing mattered for them. For the teams that didn't rush efficiently and lost, it wasn't good for them (and there could be a lot of intermediate cases). Not sure I would conclude from this rushing doesn't matter, period?
A guessing game of a team's wins
"Running the ball does not affect winning as much as you think. To illustrate this point, consider this guessing game. Suppose you want to guess how many games a team will win during the regular season. Without any other data, it makes sense to guess 8, the average number of wins in a 16 game season.
From 2003 through 2012, this estimate would be wrong by 3.1 wins. In technical jargon, 3.1 is the standard deviation of actual wins from the guess of 8. In normal people language, it says 2 of 3 teams will be within 3.1 wins of the guess. About two thirds of NFL teams won between 5 and 11 games between 2003 and 2012.
With the rush efficiency for each team, how much better does your guess get? The right panel of the visual below shows how rush efficiency relates to wins for every NFL team from 2003 through 2012. Simple linear regression gives the best fit line through the data.
The regression line gives a new guess about the number of games a team will win. For example, suppose a team has a rush efficiency of 0.6 yards per carry. Instead of guessing 8 wins for this team, the line gives 8.7 wins for this team.
How much better are these new guesses? Not much. The error only drops from 3.1 wins to 3.03 wins. In technical jargon, rush efficiency explains only 4.4% of the variance in wins. You might as well guess randomly.
The results get better using pass efficiency, as shown in the left panel. The error in estimating wins drops from 3.1 to 1.96. Pass efficiency explains 62% of the variance in wins in the NFL. The strong relationship is clear from the visual.
In college football, rush efficiency correlates more strongly with wins than in the NFL. Teams like Alabama, Stanford and Wisconsin have won with a power running game and a physical front seven on defense. The insignificance of running the ball is unique to the NFL."
