To win in the NFL, you have to pass the ball and be able to stop the pass.

You were expecting "run, and stop the run?" Welcome to the 21st century. If you liked three-yards-and-a-cloud-of-dust tactics, watch "Knute Rockne, All American."

Just about every coach will tell you that running and stopping the run are the keys to winning. They say this because a) that's what their coaches, and their coaches' coaches, told them, and b) they think it is what you want to hear. But instead of listening to what coaches say, let's look at what coaches do. And with the help of the Football Outsiders' database, let's really break things down so we can see how coaches and teams really try to win games.

Here's a hint: It involves neither three yards nor dust clouds.

Spread Out and Shotgunned: Let's start with the run-pass breakdown for 2011: Teams ran on 39.6 percent of snaps and passed on 60.4 percent of snaps.

You may see slightly different percentages in the official tallies, but these figures list quarterback scrambles as passing plays, because that's what the coaches called. So your favorite head coach may stress "balance" at every single press conference, but if balance means a 50-50 run-pass split, he is doing a lousy job of finding it.

The following table separates runs and passes by down and distance.

Table 1: Run and Pass Percentages by Down

  Run % Pass %
First Down 49.3 50.7
Second Down 41.1 58.9
Third-and-Short (0-2 yards) 53.0 47.0
Third-and-Medium (3 to 7) 9.9 90.1
Third-and-Long (8-plus) 8.2 91.8

Coaches still vie for a 50-50 split on first down, and they still prefer handing off (very slightly) on third-and-short. On other downs, get ready for a pass. Overall, a team is nearly five times more likely to pass than throw on third down.

The supremacy of the passing game is most obvious when a team lines up in shotgun, which some teams now do just about all the time. Fans of a certain age can remember that when Roger Staubach dropped into shotgun on third-and-10 for the 1970s Cowboys, it was as exotic as taking a snap on Jupiter. Well, not anymore:

Table 2: Shotgun vs. Under Center Play Percentages

Play % of Snaps
Shotgun, Pass 35.1
Shotgun, Run 5.4
Under center, Pass 25.2
Under center, Run 33.9

A modern NFL team is more likely to line up in shotgun and throw than it is to line up in traditional formation and hand off. And the percentages are deflated by a handful of coaches who are shotgun holdouts; while the Texans used the shotgun only 19 percent of the time, the Lions used it for 68 percent of snaps, the Bills 58 percent and the Panthers 57 percent. (The Patriots have an all-shotgun, all-the-time reputation but used it for "only" 51 percent of snaps last year.) For many teams, shotgun formations are base formations.

With all of those shotgun formations come three-to-four wideout sets, empty backfields and other tactics that make fullbacks update their LinkedIn accounts. We think of two receivers, two backs and a tight end as "base" personnel, but that perception is increasingly off-base:

 

 

 

Table 3: Play Percentages by Formation

Formation % of Snaps
Empty Backfield 6.3
1 RB, 4 WR 3.9
1 RB, 3 WR, 1 TE 37.8
1 RB, 2 WR, 2 TE 18.5
"Base" 17.7
2 RB, 2 or 3 TEs 7.6
3 RBs (Full House) 0.7

These percentages are based on the formation, not the players. So if Matt Forte was in the slot, he was counted as a receiver, not a running back. The numbers do not add up to 100 percent because of fake punts and field goals, wildcat plays and other exotica. Oh, and don't worry about end-of-game kneels or spikes to stop the clock; they were purged from the data before we started.

The numbers show that the base personnel package in the NFL is a three-receiver set, which is more common than the traditional package and the two-tight end, one-back look combined. When the starters are introduced at the beginning of a telecast, the slot receiver should be listed, not the fullback, for all but a handful of teams. (Many telecasts already do this.)

Different teams have different tendencies, of course. The Ravens still used a two-back backfield 59 percent of the time last year, more than twice the league average. The Bills use an empty backfield 18 percent of the time and three or more receivers on 82 percent of snaps. The trend clearly points to more spread formations and more passing. Even the Ravens appear to be opening things up with a no-huddle offense. Running backs must be ready to line up in the slot. Fullbacks should consider rugby.

Throw More, Throw Shorter. Ah, but where are all of these passes going? Do quarterbacks throw deep anymore? Or are all of these passes mamby-pamby tunnel screens that look great on the stat sheet but amount to little more than a bunch of three-yard gains?

Let's break down NFL passes by length and chunk them into five categories: Screen (behind the line, whether it is a true screen or not), Smash (zero to five yards), Short (six to 10), Medium (11 to 20) and Long (20-plus). These breakdowns are based on air lengths of passes, not yardage results; a two-yard pass with a 60-yard run after the catch is a two-yard pass. As you might expect, quarterbacks throw a lot of passes that might not travel across your living room. But there are still plenty of old-fashioned bombs in the air.

Table 4: Passes and Results By Length

  % of Passes Completion % Yards Per Attempt
Screen 11.7 80.3 5.1
Smash 34.9 66.1 4.9
Short 19.9 61.0 6.7
Medium 22.1 53.0 9.9
Long 11.0 34.4 12.9

Teams may pass 60 percent of the time, but two-thirds of those passes travel 10 yards or fewer down the field. If you want to be a curmudgeon, you can gripe about how today's quarterbacks only have to throw Pop Warner passes, when ol' Slingin' Sammy Baugh had to fire the ball 40 yards through a hailstorm every time he dropped back. Here's a more forward-thinking interpretation of the data: Those short passes have become so important that quarterbacks have no margin for error. Every screen must be timed perfectly, every slant must hit the receiver on the hands in stride and the reads must be as accurate as the throws. Old quarterbacks were muscle cars. Modern quarterbacks are supercomputers. Traditionalists can take heart that, while the NFL may be pass-oriented, it is not gadget-oriented. Spread offensive principles may have brought more six-yard passes, but few of the playground tactics that now dominate college football have found their way into the NFL.

Here's a breakdown of how often several strategies, including several gimmick plays, are called in the NFL:

 

 

 

Table 5: Play-Action, Screens, Draws, Miscellanea

Play Type % of Snaps
Play Action Pass 11.3
Play Action "Bomb" 2.6
Running back Screen 2.5
Draw Play 2.2
WR-TE Screen 2.1
Designed QB Run 0.7
Reverse/End Around 0.5
Wildcat 0.3
Shovel Pass 0.2

College quarterbacks in spread-option offenses might carry the ball a dozen times per game, scrambles not included. They then arrive in the NFL and discover that designed keepers account for less than one percent of all plays, and that's with Tim Tebow's 20-carry adventures in Denver factored in. The wildcat lives on in New York and Buffalo, but nowhere else. "Tunnel" and "bubble" screens to receivers, which have become as ubiquitous on autumn Saturdays as leaf raking, are not nearly as common at the NFL level.

Play-action, screens and draw plays are time-honored techniques for catching defenses off guard, but the only tactic that constitutes a major element of most game plans is the play-action pass. Teams may not hand off much anymore, but they still fake a lot of handoffs, which is ironic until you realize how little offensive strategy has changed under the hood. Shotgun sets and spread formations are mostly bells and whistles attached to the same concepts, blocking schemes and pass patterns that Vince Lombardi and Paul Brown used.

And if Brown or Lombardi got a look at today's quarterbacks and pass-friendly rules, he would throw the ball 60 percent of the time, too.

Air Defense Capability. Now that we know the exact scope of the aerial assault offenses are unleashing, let's take a look at how defenses are trying to stop it.

As you know, there are two primary base defenses in the NFL: the 4-3 and the 3-4. As you probably also know, those labels are nearly meaningless. Most coaches use a variety of defensive fronts during the course of a game, and pass-happy offenses force defenses to use five or more defensive backs for a high percentage of snaps.

Here's a breakdown of the most common personnel groupings in the NFL. There's a little bit of guesswork here, because some teams have "linebackers" who are 270 pounds and line up with their hands on the dirt for most plays. But if a coach says he's a linebacker, he's a linebacker. Also, goal-line plays were removed from the data; otherwise you might see a misleading number of five- or six-linemen formations.

 

 

 

Table 6: Defensive Formations

Formation % of Snaps
4-3-4 30.7
4-2-5 25.3
3-4-4 17.2
3-3-5 8.2
2-4-5 6.6
4-1-6 4.5
2-3-6 2.9
7 or more DBs 0.7

Teams use five or more defensive backs on 41.7 percent of snaps. A few tables ago, we saw that offenses use three or four wide receivers on … 41.7 percent of snaps. If only all of life's percentages worked out so neatly.

As with offensive formations, defensive strategies vary from team to team. The Giants have a "heavy nickel" package, which they used on 59 percent of snaps last year. The Packers used their 2-4-5 defense on 61 percent of snaps. The super-conservative Bears used a 4-2-5 defense 52 percent of the time, a 4-3-4 defense 47 percent of the time, and other formations exclusively at the goal line or in Hail Mary situations. Unlike offensive formations, though, defensive sets are dictated by opponents. Lovie Smith would have kept the Bears in a 4-3-4 set 100 percent of the time if he did not have to contend with the wide-open passing of the Packers and Lions.

No matter what personnel they deploy, defensive coaches must decide how many defenders will rush the passer and how many will drop into coverage. With receivers spread all over the field, defensive coaches must weigh the merits of the pass rush with the risk of leaving defenders in one-on-one matchups. After careful weighing, most defensive coaches do what coaches have been doing for the last five decades or so: rush four and drop seven.

Table 7: Pass Rush and Blitz Frequencies

# of Rushers % of Pass Plays Sack %
3 7.1 4.1
4 62.2 5.8
5 22.2 8.6
6 6.6 8.8
7-8 0.2 10.3

Again, goal-to-go data was removed so we don't have to worry about a desperate defense rushing 10 guys from the one-yard line. The data reveals that most 3-4 defenses send at least one linebacker to blitz on passing downs. Anyone who has ever watched the Steelers should not be surprised. The data also shows sack percentages increasing with the number of pass rushers, which again is no surprise.
Not shown in the table is the yards-per-pass data. Opponents average 6.8 yards per pass play against both three- and four-man rushes. Opponents average 6.3 yards per pass play against both five- and six-man rushes. In other words, a well-timed blitz cuts about a half-yard per play off the passing game. Opponents average 7.1 yards per pass against seven or more pass rushers, but coaches call such "jailbreaks" only when they can trade the high risk for the potential high reward.

Go For It! There's one last bit of strategy to break down, and you may want to send this segment along to the Falcons fan in your life. Teams have become more aggressive in recent years about "going for it" on fourth downs. There's a good reason why coaches are gambling more: the odds are in their favor.

This final table (hooray!) shows fourth-down percentages broken down in three different ways. The first is the overall fourth-down percentage across the NFL. The second shows the fourth-down percentage in the first three quarters only. Why leave out the fourth quarter? That's when teams that are desperately behind start going for it on fourth-and-15 because they have no choice. Those crossed-finger attempts skew the results in favor of the defense. The final breakdown is for fourth-and-one, Mike Smith's favorite down and distance.

 

 

 

Table 8: Fourth Down Conversion Rates

Overall 42.9
First 3 Quarters 54.0
Fourth-and-1 52.0

Once desperation strategies are filtered out, teams have a better than 50 percent chance of converting on fourth down.

Still, some coaches are more risk averse than others. Football Outsiders keeps track of how often coaches go for it in likely situations: fourth-and-short, in opponent's territory, game still undecided. Bill Belichick has gone for the conversion 21.4 percent of the time in those circumstances in his career, making him one of the most aggressive coaches in history. His mentor, Bill Parcells, tops him by going for it 23.4 percent of the time in favorable situations. Our pal Mike Smith is rising through the ranks by going for it 21.0 percent of the time, and some failed conversions in the playoffs probably won't shake his resolve. On the other side of the coin, Ron Rivera of the Panthers went for the conversion just twice in favorable circumstances last year. Somebody should remind him that no one wants to try to defend Cam Newton on fourth-and-one.

No matter how aggressive Smith or Belichick are, most research indicates that teams should go for it far more often on fourth down than they currently do. But just as spread formations and shotgun offenses hide an undeniable conservative streak in offensive strategies (lots of engineering to produce six-yard passes) and the four-man pass rush still dominates defensive thinking, fourth-down tactics are still rooted in the era of muddy fields and quarterbacks who doubled as punters.

Strategy evolves slowly in the NFL. A decade from now, we will be watching a game with a little more passing, a little more defensive diversity and a little more fourth-down gambling. But not much.