The effect of pressure

How many times throughout the season do you hear a fan cry out, "We should have brought more pressure," or "The only thing a prevent defense prevents is victory"? Truth is, many casual fans want their defenses to blitz, fly around, gang tackle, and create turnovers on every play. Unfortunately, that is simply not possible.

While coaches know this to be true, they will still gladly tell their fans what they want to hear. Is there a coach in the nation who doesn’t use terms like aggressive, attacking, and dictate the pace when talking about what to expect from their defensive units? It’s understandable. No coach is going to get the fan base excited about his defense by using words like sound, or vanilla.

But what type of defense a team ultimately runs often boils down to a compromise between a desired philosophy and current personnel. A great coach will coach to his players' strengths and put them in the best situation possible to succeed.

Football is essentially a chess match where each side of the ball is trying its best to disguise its intentions. Neither the offense nor the defense wants to play in a reactionary fashion. It is each unit's goal to make the opposition play on its heels once the ball is snapped.

Obviously, offenses are at an extreme advantage in this respect. Being the ones with the ball and the one determining when the ball is snapped, offenses can dictate much more of the game. Some offenses hurry things up. Some huddle up. Some hurry-up, check with their coaches, have a mini-huddle, then rush the snap to beat the play clock. Every strategy is meant to put the respective offense in the most advantageous position as possible. So what can defenses do to take back some of this advantage? Well, they can blitz.

When defenses bring additional pressure, it is the offense that must react. Whether it is an adjustment in the type of play call, the protection, or just a simple alteration in a route, bringing blitzers forces offenses to into a reactionary position. The tables are somewhat turned.

In the charting from this past college football season, there were a total of 1,690 pass attempts in which a defense brought five rushers, and 325 plays when a defense brought six rushers (most base defensive schemes bring just four rushers). It should be noted that it is often difficult to tell the difference between five- and six-man pressure if a defense is playing an aggressive man-to-man coverage behind it. Many teams will Green Dog, or blitz to engage, a linebacker who is covering a running back or tight end who stays into block. As covered in that piece, when this happens, the man in coverage essentially blitzes and the five-man rush quickly turns into a six-man rush. For charting purposes, we simply did the best we could to distinguish the number of rushers.

The tables below shows the number of charted plays in which blitzes resulted in either a sack or pressure. The charting of pressure was another judgment call on behalf of the charter. Generally, if the pass rush resulted in a sack, forced scramble, rushed throw, or hit on the quarterback as he was throwing, then it was considered a pressure.

As you can see, the frequency with which five- and six-man rushes produced sacks was nearly identical. Both types of rushes resulted in sacks just fewer than 10 percent of the time. But with pressures, the numbers show much more of a discrepancy. While 28% of five-man rushes resulted in pressure, over 42% percent of six-man rushes resulted in it. The figures back up logic, where the more rushers a defense brings, then the greater the odds someone breaks through.

The above is the grouped outcomes of every charted play involving five- and six-man rushes.

If you combined negative yards, incompletions, and interceptions into one group and called them bad plays, then defenses forced bad plays 45% of the time when bringing five rushers, and 52% of the time when bringing six. That’s a fairly high percentage, especially when many teams automatically check to quick-hitting hot routes like bubbles and hitches once they recognize pressure.

Against five-man rushes, the numbers show that offenses converted about three-fifths of their third downs when it was 3rd and 1-4 yards, a third of their chances when it 3rd and 5-8, and about one-fifth of their chances when it was 3rd and 9+.

Note from Bill: This adds further confirmation to the lines we've established between standard downs and passing downs. With between one and three yards to go on third downs, offenses hold a significant advantage because they can run or pass effectively. The balance begins to shift on third-and-4, then goes fully in the defense's favor on third-and-5 as offenses are forced to go one-dimensional.

The figures against six-man rushes proved to be a bit more cluttered, potentially due to the smaller sample size. While the extremes were similar to those of the five-man rushes, the intermediate data for six-man rushes were not nearly as consistent.

The overall takeaway from the third down charting, and third down conversions in general, is that what an offense does on first and second down is just as important, if not more important, than what they do on third down itself. If an offense puts itself in a third-and-short situations, chances are they will convert the first down. If they find themselves in a third and long, get the punt team ready.

And to all those Sunday Morning Quarterbacks out there, just remember, the next time you’re calling for more pressure, while you might expect this to happen...

...you may instead end up with this.