Ray Horton promised the Arizona Cardinals would adopt an aggressive mentality on defense when the team named him its coordinator.
Horton has delivered on that promise.
2011 Pass-rush Counts: Number of Rushers
The Cardinals have sent five or more pass-rushers on 48.2 percent of plays when opponents attempted a pass or took a sack, easily the highest percentage in the NFC West.
Horton could be acting out of desperation as much as from philosophy. As the first chart shows, the Cardinals rank last on defense in Total QBR allowed when sending four or fewer pass-rushers, according to ESPN Stats & Information. The numbers improve modestly when the Cardinals send five or more pass-rushers. Either way, though, Arizona is failing to affect quarterbacks as desired.
And with an offense that has struggled to find consistency, Arizona hasn't built the leads that force opposing offenses to take additional chances.
2011 NFC West Defenses: Four or fewer pass-rushers, by QBR
The charts also say plenty about the St. Louis Rams' predicament in the secondary. Opposing quarterbacks become quite a bit more effective, as measured by Total QBR and NFL passer rating, when the Rams send more than five pass-rushers. This reflects an inability to get pressure quickly enough and an inability to hold up in the secondary when sacrificing coverage players in pursuit of a pass rush.
2011 NFC West Defenses: Five or more pass-rushers, by QBR
The San Francisco 49ers, meanwhile, have sent five or more rushers less than 20 percent of the time. They've been able to count on pressure from defensive ends Justin Smith and Ray McDonald, who attack from the inside on obvious passing downs. They've also gotten good pressure contributions from outside linebackers Aldon Smith and Ahmad Brooks.
Why commit additional players to pressure schemes when four are getting enough pressure? The 49ers got pressure with three-man fronts against Detroit in Week 6.
The Seattle Seahawks' numbers stand out pertaining to sack percentages. The team gets sacks on 2.8 percent of pass plays when sending four or fewer rushers, the lowest percentage in the division. The percentage climbs to a division-high 11.7 percent when sending added pressure. The Seahawks have gotten 35 percent of their sacks from linebackers and defensive backs. The percentage is 18.2 for St. Louis, the other team in the division running a 4-3 defense.