Philadelphia Eagles

Outside of the New England game, all the games were good and exciting, from the final goal line stand by the Eagles, to the win with ten seconds left by the Vikings. The Jacksonville Jaguars are just not well managed by this system. It was easy to see that through the year that they were a boom or bust team. They could win big or lose big, and in the game with the Steelers, they were enough in “win big” mode that the Steelers could not keep up.

Philadelphia won because of their stout defense, a Nick Foles that gave them a AYA of 8.2 for the game, much akin to Carson Wentz’s average.

To remind people, the 2017 worksheet is here, and the methodology is here. The odds for the next round are below.

Conference (NFC/AFC) Playoff Odds
Home Team Visiting Team Score Diff Win Prob Est. Point Spread
Philadelphia Eagles Minnesota Vikings -0.604 0.353 -4.5
New England Patriots Jacksonville Jaguars 1.872 0.867 13.9

The first round is over and in terms of predicting winners, not my best (by my count, 1-2-1, as we had Jax and Bills in a de facto tie). I was pleased that the model got Rams and Atlanta correct, and the Sunday games all came down to the wire. One or two plays and my formal results would have been impressive. Still, back to the predictions for this week.

To add some spice, we will predict results for New Orleans normally, and also as if Drew Brees is elite. Values in parentheses are the elite numbers. With elite status or no, Minnesota is still favored in this data set.

The only home team not favored is Philadelphia. We discussed this in part in this article.

Second Round Playoff Odds
Home Team Visiting Team Score Diff Win Prob Est. Point Spread
Philadelphia Eagles Atlanta Falcons -0.878 0.294 -6.5
Minnesota Vikings New Orleans Saints 1.231 (0.484) 0.774 (0.619) 9.1 (3.6)
New England Patriots Tennessee Titans 1.674 0.842 12.4
Pittsburgh Steelers Jacksonville Jaguars 1.915 0.872 14

Summary: Replacing Wentz with Foles removes about 6.5 points of offense from the Philadelphia Eagles, turning a high flying offense into something very average.

Last night the Atlanta Falcons defeated the LA Rams. Now we’re faced with the prospect of the Falcons playing the Eagles. I have an idiosyncratic playoff model, one I treat as a hobby. It is based on static factors, the three being home field advantage, strength of schedule, and previous playoff experience. And since it values the Eagles as 0.444 and the Falcons as 1.322, the difference is -0.878 (win probability in logits). The inverse logit of -0.878 is 0.294, which is the probability of the Eagles winning, and an estimated point spread would be a 6.5 point advantage for the Falcons.

Another question that a Falcons or Eagles fan might have is how much is Carson Wentz worth as a QB, in points scored? We can use the adjusted yards per attempt stat of Pro Football Reference to estimate this, and also to estimate how much Carson Wentz is better than Foles. We have made these kinds of analyses before for Matt Ryan and Peyton Manning.

Pro Football Reference says that Carson Wentz has a AYA of 8.3 yards per attempt. Nick Foles has a AYA of 5.4. Now lets calculate the overall AYA for every pass thrown in the NFL. Stats are from Pro Football Reference.

(114870 yards + 20*741 TDs – 45*430 Ints) / 17488 Attempts
(114870 yards + 14820 TD “yards” – 19350 Int “yards”) / 117488 Attempts
110340 net yards / 17488 yards
6.31 yards per attempt to three significant digits

So about 6.3 yards per attempt. Carson Wentz is 2 yards per attempt better than the average. Nick Foles is 0.9 yards less than the average. The magic number is 2.25 which converts yards per attempt to points scored per thirty passes. So Carson, compared to Foles, is worth 2.9 * 2.25 = 6.5 points per game more than Foles, and 4.5 points more than the average NFL quarterback.

This doesn’t completely encompass Carson Wentz’s value, as according to ESPN
‘s QBR stat
, he account for 10 expected points on the ground in 13 games, so he nets about 0.8 points a game on the ground as well.

Now, back to some traditional stats. The offensive SRS assigned to Philadelphia by PFR is 7.0 with a defensive SRS of 2.5. If Carson Wentz is worth between 6.5 and 7.3 points per game, then it reduces Philadelphia’s offense to something very average, about 0.5 to -0.3. That high flying offense is almost completely transformed by the loss of their quarterback into an average offense.

Note: logits are to probabilities as logarithms are to multiplication. Rather than multiplying probabilities and using transitive rules, you just add the logits and convert back. Logarithms allow you to add logarithms of numbers rather than multiplying them.

I didn’t expect another trade of this magnitude, and so quickly. But let’s crunch the numbers on this trade, and compare them to the 2016 Titans-Rams trade.

The Browns received from the Eagles, the #8, #77 and #100 picks in this draft. In 2017 they receive the Eagles first round pick. In 2018 they receive the Eagles 2nd round pick. The Eagles have received the #2 pick in this draft, and the Browns 4th round pick in 2017.

For the purposes of this calculation, we assume the Eagles will pick 20th in 2017 and 2018, and that the Brown in 2017 will rise from 2nd to 10th.


The AV costs of the 2016 Eagles Browns trade.
Eagles Browns Results
Pick Average AV Pick Average AV Delta AV Risk Ratio
2 46 8 40
(138) 8 77 12
100 17
(20) 29
(52) 22
Total 54 Total 120
66 2.22


The Delta AV for both trades are the same, but since the Eagles received a lot less AV, the relative ratio of AV given to AV received is higher. The trade cost is the same, but the purchase is more highly leveraged.

I’ve been reading a ton of books. One of these is Robert W. Peterson’s “Pigskin”, which has been an interesting read so far. I’m roughly in the late 1940s in this book, which starts with the beginning of professional football and ends with the NFL championship in 1958. What has caught my eye are Mr. Peterson’s comments about the spread of the T formation in the 1940s. He describes the Bears 73-0 NFL Championship victory over the Redskins. Later, when describing the switch of the Redskins to the T in 1944, he gives this accounting of the state of the football world in 1944: (1)

By that year, more than 50 percent of college teams has converted to the T formation. So had most pro teams. Henceforth, the old single-wing formula of “three yards and a cloud of dust” as the ideal offensive play would go the way of the rugby ball in pro football

The adoption was not immediate upon the end of the 1940 season, however, and teams, coaches, and whole conferences that were successful with the single wing (or Southwestern spread) tended to stick with it. For example, in Tom Landry’s autobiography, he notes that Texas made the switch in 1947, after Dana Bible retired.(2) Y. A. Tittle’s memory of the conversion is (3)

If I remember correctly, the first Southwestern conference team to switch to the T formation from the single- and double-wing formations was Rice University, followed by Georgia and Louisiana State.

The quote above mixes the SEC and the Southwest conference, but still.. LSU switched in 1945. I’m just not sure which of the 50% of college football teams were converting. Army and Notre Dame are well known early adopters, but as a counterexample, in 1947, Fritz Crisler won a national championship with a single wing offense at Michigan.

Dan Daly, when discussing the effects of the 73-0 Bears win over the Redskins, noted:(4)

Only one other NFL team, the Philadelphia Eagles, switched to the T the next season. And as late as 1944, both clubs that played in the championship game, the Green Bay Packers and the New York Giants, used the single wing or some variation.

Paul Brown, the head coach of Ohio State from 1941 to 1943, was the first coach to see Don Faurot’s split T in action, in his very first game as Ohio State’s head coach, but then says of his game with Clark Shaughnessy’s Pittsburgh squad in 1943 (5)

It was my first real look at the T formation with flankers and men in motion, however, and it was the kind of football I later assimilated into my own system with the Browns.

So from 1941 to 1943, the “Bears” T was largely unknown in the Big 10. Paul Brown then learned the T while serving in the armed services. In 1946 and 1947, in the first two AAFC championships, Brown’s T was pitted against the single wing offense of the New York Yankees.(6)

As Dan Daly notes, the lack of players trained in the new offense slowed the T formation’s spread.(7)

In the early ’40s, the Bears and the Eagles – the only two T-formation teams – drafted an unusual number of Shaughnessy’s Stanford players because the Cardinal were the lone major college team using the offense.

Dan Daly later writes (8)

By the end of the decade, though, five out of seven college teams played some form of the T. Suddenly it was the single-wing Steelers who were having trouble finding players to fit their system.

And it does make sense. There were some early adopters who ran into Luckman, or Shaughnessy, or former Bears quarterbacks and coaches, but a lot of coaches learned the T while serving in the armed services during the war, coaching or playing in service teams. So it wasn’t the early 1940s when the transition occurred, as far as I can tell. Instead, it was the mid to late 1940s when the T became dominant. The conversion was not “immediate”. It took 3-4 years to gain steam, and a decade for it to dominate.


There were only ten pro teams in 1944, and it’s entirely possible that most NFL teams were running a T by 1944 (By my count, Chicago, Philadelphia, Washington, and Cleveland are using the T by 1944. Green Bay and New York are not. The other four – Brooklyn, Boston, Detroit, and Card-Pitt – I’m not sure of). Green Bay switches to the T in 1947, New York in 1949.

Army’s first use of the T is in the 1941 Army-Navy game.(9) Notre Dame had Halas’s players assist with the conversion in 1942. Clark Shaughnessy coaches Maryland in 1942 and then Pittsburgh in 1943.

1944 is an unusual year to use as a baseline, because so many coaches and players were in the armed services. That may in fact have aided the transition, as so many coaches with a traditional single wing background found themselves coaching alongside experts in the T on service teams.

For those who have never read Ron Fimrite’s article in Sports Illustrated about the Stanford Indians’ 1940 season, just do it. It’s one of the great short articles on football. The link is given in the bibliography.


1. Peterson, Chapter 8.

2. Landry and Lewis, p. 74.

3. Tittle, Chapter 5.

4. Daly, Chapter 3.

5. Brown and Clary, p. 101.

6. Brown and Clary, pp. 181-182.

7. Daly, Chapter 3.

8. Daly, Chapter 3.

9. Roberts, Chapter 2.


Brown, Paul, and Clary, Jack, PB: The Paul Brown Story, Atheneum 1980.

Daly, Dan, The National Forgotten League: Entertaining Stories and Observations from Pro Football’s First Fifty Years, University of Nebraska Press, 2012. [ebook]

Fimrite, Ron, “The Melding of All Men, Suited to a T”, September 5, 1977. “Sports Illustrated”. retrieved July 28, 2013.

Holland, Gerald, “The Man Who Changed Football”, February 3, 1964. Sports Illustrated. retrieved July 28, 2013.

Johnston, James W. ,The Wow Boys: A Coach, a Team, and a Turning Point in College Football , University of Nebraska Press, 2006.

Landry, Tom, and Lewis, Gregg,Tom Landry: An Autobiography, Harper Paperbacks, 1990.

McGarr, Elizabeth, “The Top 20 Greatest Moments”, August 20, 2008. “Sports Illustrated”. retrieved July 28, 2013.

Peterson, Robert W., Pigskin: The Early Years of Pro Football, 1997. [ebook]

Roberts, Randy, A Team for America: The Army-Navy Game That Rallied a Nation at War , Houghton Mifflin Harcourt, reprint ed 2011. [ebook]

Tittle, Y. A, and Clark, Kristine S.,Nothing Comes Easy: My Life in Football ,Triumph Books, 2009. [ebook]

Zimmerman, Paul, in “Letters”, December 22, 1997. “Sports Illustrated”. retrieved July 28, 2013.

In 1947, defensive theory in football had not yet advanced to the level of offensive theory. I’m saying this because the focus of defensive line play was gladitorial in nature: you would beat the man in front of you, pursue the ball carrier and tackle, preferably with the best form possible. Adjustments were rare. People had to accommodate man in motion but that was about it. The notion of a defensive key isn’t even talked about (1).

In the late 1940s to mid 1950s, defensive linemen were somewhat interchangable, and there were no specific guidelines for the sizes of defensive tackles, defensive ends, or middle guards. The roles of these linemen weren’t as detailed and specific as they are in modern days. There were big powerful immobile linemen, and smaller, faster, more nimble linemen. And though people like to think of linemen falling back into zones as a modern invention, the tactic was used in Steve Owen’s 6-1 Umbrella, and sees time in the pages of Dana Bible’s book:

Linemen falling back and into coverage was a common tactic in 1947.

Linemen falling back and into coverage was a common tactic in 1947.

The idea, therefore, of a middle guard falling back into coverage wouldn’t have caused anyone in 1947 to blink an eye. So when you have a middle guard with sprinter’s speed, a guy like Bill Willis,

Cleveland Browns all pro middle guard Bill Willis (1946-1952). As big as the centers of his time with sprinter's speed.

Cleveland Browns all pro middle guard Bill Willis (1946-1952). As big as the centers of his time with sprinter’s speed (2).

the idea that he should be a part of coverage would have been expected. Good linemen would fall back from the line and into coverage when the situation demanded. Linemen rushed yes, but behaved more like modern linebackers when they had to.

“He often played as a middle or noseguard on our five-man defensive line, but we began dropping him off the line of scrimmage a yard because his great speed and pursuit carried him to the point of attack before anyone would block him” (3)

So why is this important? It’s important because the dominant defensive front from 1950 or so through 1955 is a five man front, often a 5-2 Eagle. An example comes from this screen shot of video of the 1953 NFL championship


when diagrammed, would look something like this:

Typical five man front from early 1950s NFL football.

Typical five man front from early 1950s NFL football.

And therefore, the appearance of 4-3 fronts, as a product of a middle guard digging into the “bag of tricks” a lineman was supposed to know, should have been expected. 4-3s would have appeared as a poor man’s prevent defense, or as a response to specific game events, like quarterbacks throwing the ball just over the head of Chicago’s middle guard, Bill George.

…in a game against the Philadelphia Eagles, George made a now historic move that permanently changed defensive strategy in the National Football League.

On passing plays, George’s job was to bump the center and then drop back. George, noting the Eagles success at completing short passes just over his head, decided to skip the center bump and drop back immediately. Two plays later he caught the first of his 18 pro interceptions. While no one can swear which middle guard in a five-man line first dropped back to play middle linebacker and create the classic 4-3 defense, George is the most popular choice.

This game dates to 1954. Andy Piascik’s book claims that in the regular season game between the Detroit Lions and Cleveland Browns in 1952, the Lions employed a 4-3 (4). I’d suggest though, in the absence of any evidence to the contrary, that these 4-3s fall into the form of an adjustment to the 5-2, as opposed to an integral coordinated defensive system.

The deal is, by 1956, Tom Landry, as the defensive coordinator of the New York Giants, has a 4-3 that isn’t anyone’s adjustment to something else. It’s a full blown base defense, a creation of his own hard work and imagination. It’s a largely 1 gap, keying defense, with distinct assignments to the linemen. Linemen have to fill gaps and keep the offensive line from getting to the middle linebacker. The middle linebacker roams, tackles, covers his two gaps. The initial Landry defenses have been lavishly detailed in the two volume text “Vince Lombardi on Football“, because these were the defenses Vince took with him to Green Bay.

And while what video I can watch in the period from 1948 to 1955 has yet to yield a single 4-3, the Giants live in it in the 1956 Championship game, and after some initial five man line in the 1957 Championship game, Detroit soon switches to a 4-3 and stays in it.

All this lends credence to the words of Paul Zimmerman (5)

Here and there the 4-3 popped up around the league. The Eagles got into a form of it when they had their middle guard, Bucko Kilroy, stand up, though at 258 pounds he hardly had true middle-linebacker responsibilities. The Redskins tried it, lifting middle guard Ron Marcinak and substituting a linebacker, Charley Drazenovich.

Landry graduated from player to player-coach to defensive coach under Jim Lee Howell. Vince Lombardi ran the offense. In 1956 the Giants drafted a tackle from West Virginia, Robert Lee Huff, nicknamed Sam, who had been born to play middle linebacker in the 4-3, and that became the Giant’s official standard defense. By 1957 everyone was in it.

So the real question is, how much of this 4-3 defensive system was prior art? Not the positions, mind you, but the components. The keys, the coordination, the pieces? I think the minimum you need to make such a defense are these three elements.

1. Film study. Without it you can’t really predict trends.
2. Two platoon football. Otherwise, you’re teaching one player offense 80% of the time.
3. A modern coaching staff, with full time assistants.

It’s very clear that Paul Brown’s staff with the Cleveland Browns has these three elements in the 1950s, but I don’t see signs that they were unusually innovative on defense. Instead, what you see are things like references to three man single safety backfields (6), and signs that they were working within the status quo of the times.

One resource I’d love to get my hands on is the writings of the former Cleveland Browns linebacker, Hal Herring (7). He played for the Browns for three years, starting in 1950. Later, he wrote a dissertation that was titled “Defensive Tactics and Techniques in Professional Football.” I’m not close enough to a research library to know if it can easily be obtained, but back in the day when I was writing my own dissertation, we had to make dissertations available to just about anyone who wanted a copy.

Update: correction on the Bill George date.


Notes and References

(1) Keys and tells are different beasts. A tell is Dan Fouts giving away run or pass in 1979 with his feet placement. An example of a key is a person whose actions tell you where to go and what role to play when you do. Tells have been part of football forever, akin to stealing signs. Keys are elements of the game that have to be built into the defense and coached.

(2) Image from Special Collections, Cleveland State University Library.

(3) Paul Brown, quoted by Goldstein.

(4) Piascik, Chapter 11. The exact quote is:

“I think the 4-3 defense originated with him [Parker] and his coaches,” Dub Jones said of the Detroit team that so stifled Cleveland in that first ever meeting between the two teams. “They threw that in our face in ’52 and it was tough for us to cope with, having not faced it.”

(5) Zimmerman, Chapter 6.

(6) Brown and Clary, p 220, has this interesting blurb regarding the 1951 NFL championship:

For several years, our secondary had never declared a strong side of our opponent’s offensive formation until it saw which direction the fullback was going, and though we had gotten by with this strategy, it put a great burden on Cliff Lewis, the middle safety in our three-man secondary.

(7) Piascik, Chapter 8.


Bible, Dana X, “Championship Football”, Prentice-Hall, New York, 1947.

Brown, Paul and Clary, Andy, PB: The Paul Brown Story, Atheneum, New York, 1979.

Goldstein, Richard, “Bill Willis, 86, Racial Pioneer in Pro Football, Dies”, New York Times, Nov. 29, 2007, accessed Jun 7, 2013.

Piascik, Andy, The Best Show in Football: The 1946-1955 Cleveland Browns – Pro Football’s Greatest Dynasty [ebook]

Zimmerman, Paul, New Thinking Man’s Guide to Professional Football, Harper Collins, 1984.

I believed, in the immediate aftermath of the 2011 season, that with Jason Peters at left tackle, the least of Philadelphia’s worries would have been the tackle position. Instead, he was injured in the off season. In September, Philadelphia center Jason Celce went down with a season ending injury. In the New Orleans game, Todd Herremans suffered a season ending injury, and going into the Dallas game, starting guard Danny Watkins had been out with a sprained ankle.

Losing Todd Herremans: deal breaker for the Eagles? (Image from Wikimedia).

So, in week 10, the Eagles had one healthy starting caliber player, and 4 backups playing on the offensive line. This loss of talent was profound, even in comparison with Dallas, which had 1 backup on the line – though Dallas RG Mackenzie Bernadeau has been pretty marginal as a starter. Simplified, losing tackles is much worse than losing a guard and a center. Result? A markedly ineffective Vick, a thoroughbred offense reduced to dog-sled pace.

No wonder announcers were hyping this as the “end of a season” for one of these teams. Most any cold blooded announcer could have figured out what was about to happen. The only question was how best to pitch it so people would actually watch.

Atlanta: I’ve been comparing the 2012 Atlanta Falcons to the 1976 Oakland Raiders, to make the case that Atlanta has a chance. But the 1976 Raiders had made it to three previous Conference Championship games, while the Mike Smith squads have never gone that far. They lack the deep playoff experience of those 1970s Raiders squads.

The fact is, all scoring stats suggest Atlanta has benefited from plenty of luck. I think, because of a better Julio Jones, that this is a better Falcons team than the 2011 team, but the coaching changes in New Orleans markedly benefited this squad. Yes, Atlanta can be beaten.

Week 9 scoring stats:

Week 10 scoring stats:

If we use the median point spread as a measure of how good Atlanta is, and select the teams within 2 points of their value, you end up with a group that includes San Francisco, New England, Minnesota, and the New York Giants. That’s a talented group of teams, but perhaps not as terrifying as Green Bay, Houston, Denver, and Chicago. Pythagoreans point out three elite teams in Houston, Chicago, and San Francisco, while simple rankings prefer the quartet of Houston, Chicago, Denver and San Francisco.

At this point, perhaps the more appropriate past comparison for the Falcons would be the 1973 Oakland Raiders. Atlanta needs to make some noise in the playoffs first.

Should anyone be worried about the Giants mid season slide? No. They always do this. The question is, will they fully recover in time to make a playoff run. That’s not something that will be entirely answered until week 17.

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