Knee-jerk reaction

THE MOST TELLING part of linebacker Brian Cushing's season-ending knee injury on Oct. 8 was the deafening silence afterward. Cushing, Houston's 2011 MVP, was the fiery leader of a swarming, stingy defense that made the team an early Super Bowl favorite. He was felled on a low blindside block by Jets guard Matt Slauson that later cost Slauson a $10,000 fine.

Yet Cushing, his teammates and even the Texans coaches were remarkably tempered in their response to Slauson's use of a cut block. Maybe that's because the technique is something of a Texans trademark. It's also another of the NFL's dirty little secrets now being exposed by an increased focus on player safety. "It's the cheapest, most cowardly play in the game," says Hall of Famer Bruce Smith, the NFL's career sacks leader. "It's a guy saying, I can't play up to your standard, so I'm gonna go directly at your knees and try to injure you."

To be clear, the NFL rulebook allows for almost every iteration of the cut block. A cut block occurs when an offensive player either dives at the knees or engages a defender and then drops to the ground. The only time the tactic is illegal is when a defender is not able to see the blocker. In that case, the block is called a peelback or crackback.

The language in the NFL rulebook, however, is murky, which leads to inconsistent officiating. That's why Slauson was fined but not flagged for what the league later called a peelback block. The NFL deemed that the hit had come from the side, hence the peelback ruling. Slauson -- and his Jets coaches -- insisted it was legal; he's appealing the fine.

The cut block should not be confused with the chop block, a (mostly) illegal move wherein one blocker engages a defender high so that a second lineman can take him out low. But even the chop block is permitted on rushes, provided it's done within the flow of the play by two linemen.

The bottom line is that the NFL has strict rules to protect the knees of quarterbacks and punters, but an offensive lineman can almost always take out a pass rusher without so much as drawing a penalty flag. It's a dangerous double standard that Packers linebacker Clay Matthews, Vikings defensive end Jared Allen and others have begun to challenge publicly. "My knee is just as valuable as Tom Brady's," Allen said recently. Adds Browns linebacker D'Qwell Jackson, the team's top tackler: "When the NFL talks about protecting defenseless players, I guess they only mean offensive players. This is my seventh year, and I've seen this stuff go on at least five times a game."

So why not just outlaw blocks below the knees? It's tricky, but teams really don't want the tactic to go away. That's because cut blocking works -- especially in Houston, where the coaches forbid the move in practice but use it in games. "The Texans couldn't say a damn word about what happened to Cushing because they cut more than anyone in the league," says former NFL lineman and cut-block aficionado Ross Tucker, now an analyst for ESPN.com and NBC Sports Network. "I would have done the exact same thing Slauson did, and I have about a million times. I thought cut blocks were a hell of a lot of fun and a great way to knock guys on their ass."

He's not the only one. Since the 1980s, almost every NFL team has used the low block as a tactical part of its offense. Cutting began as a key ingredient in Bill Walsh's West Coast scheme during the 49ers' dynasty days. Mike Shanahan, a former 49ers offensive coordinator, took the technique with him to Denver, where he won two Super Bowls with Gary Kubiak -- now the Texans coach -- as his offensive coordinator. From there, the cut block has spread to about 80 percent of the NFL.

Most West Coast offenses wouldn't work without it. Cut blocking allows outmatched or outnumbered linemen and especially running backs working in blitz pickup to slow down pass rushers. At the same time, it forces defenders to drop their hands in order to protect their knees. That opens up passing lanes for the quick, short strikes of the West Coast offense.

This season, the nastiest legal play in football is also at the heart of the zone-blocking schemes that are fueling a mini-renaissance of the run game. Through Week 9, teams were running the ball only 26.8 times per game, the lowest ever in the league. On the other hand, NFL runners were averaging 4.25 yards per attempt, within striking distance of the record 4.29 ypa from last season. Four of the NFL's top five rushers (through Week 9), including Houston's Arian Foster, operate out of zone-blocking schemes.

In zone blocking, linemen move defenders laterally, then turn and seal them off from the hole with something similar to a moving pick in basketball. To finish off a potential tackler, particularly on the back side of the play -- where an end or a linebacker is at full speed and likely to blow up the play from behind -- the blocker simply drops to the turf and impedes him. For some unlucky defenders, that cut block pins their feet and lower legs in place while the upper body continues forward until something gives. If it sounds brutal, well, it is. "You won't make friends doing it," says Tucker. "But I didn't need more friends. I needed a job in pro football."

In 2002, Tucker was released by the Redskins and claimed by Dallas. In a Thanksgiving Day game that year, Tucker found himself across the line from many former teammates. When the play called for it, Tucker went low, without hesitation. "You don't have a choice: In the NFL, you cut or you get cut," he says. "It's vicious, but it's legal, mandatory and extremely effective."

It's more than just the technical aspect that makes the cut block so brutally effective. It has a psychological impact too, because it targets such a vulnerable part of a player's body. In fact, players are far more concerned about the immediacy of a blown-out knee than the long-term implications of concussions. In a Mag poll of 48 NFL players during the offseason, 81.4 percent said they'd rather absorb a monster hit to their head than to their knees.

"Knees end a season or a career, so there's no doubt which injury guys prefer," says Panthers veteran defensive tackle Dwan Edwards. "That's why cut blocking slows you down. In the back of your mind, the rest of the game you're thinking about protecting your knees."

But because the cut block is entrenched in so many playbooks, don't expect the league to outlaw it any time soon. Each spring, members of the NFL's competition committee review tape of every catastrophic injury from the previous season. After the Cushing injury, the league promised to take a long look at cut blocks this offseason.

To its credit, the NFL has already banned all low blocks on special-teams plays. Any rule change, however, requires a three-fourths majority -- 24 votes -- from owners who rely heavily on coaches' opinions.

In other words, you'll probably be hearing the same complaints -- and in some cases, the same deafening silence -- about cut blocks a year from now.

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