Good, hard, sharp, and sure tackling is the very essence of a successful defense, and no player should hope to be placed upon a team unless he has become adept in this most important of football fundamentals. No team is going to be severely beaten, even if it has no offense at all, if it is composed of eleven good tacklers....

—GLENN SCOBEY (POP) WARNER

May 1927

On a November Sunday in Cleveland last year, Jets quarterback Mark Sanchez completed a pass to wideout Braylon Edwards in the shallow left flat. Browns cornerback Sheldon Brown jumped forward to perform the essential job that Pop Warner had described 83 years earlier: Tackle the ballcarrier. (Huddle. Repeat.) Football plays can end in various ways: with touchdowns, field goals, incompletions, fair catches, dead-ball penalties and stepping out-of-bounds. But most end with the ballcarrier being taken to the ground by the defense. It is absolute. After a tackle, whistles are blown, the ball is spotted and the offense must draw up another play and start anew.

But tackling has also become one of the most uncertain elements in the modern NFL, altered not only by evolutions in strategy (sideline-to-sideline passing attacks supplanting between-the-numbers power running) and performance (more elusive athletes with each passing year), but also most recently by rules changes designed to protect ballcarriers from injuries by limiting concussive, helmet-to-helmet hits. The pure, unbridled, bone-jarring tackle is a fading memory.

As Brown moved up on Edwards, his instincts told him to blast headlong with little regard for the consequences, tactical or physical. There are two basic ways to tackle: either "break down" into a balanced crouch to reduce the possibility of getting juked in the open field, or barrel into the ballcarrier at full speed. Brown had played his first seven NFL seasons for the Eagles under the late defensive coordinator Jim Johnson, who gave his troops only one option.

"Coach Johnson taught us to never break down, just keep running through like knives," says Brown. "And if I miss on the correct side, one of my teammates will be right behind me, running like a bat out of you know where, and he'll make the hit and maybe force a turnover. One of the knives will hit." (Ravens coach John Harbaugh, who worked under Johnson in Philadelphia, says, "Arrow through snow" that's what Jim used to say: Attack like an arrow through snow.")

As an Eagle, Brown lived Johnson's credo. In January 2007 he laid out Saints running back Reggie Bush with a blowup hit by driving hard upfield on a swing pass, a shot so monumental it made the cover of SI six months later. But here, against the Jets, Brown hesitated. The previous month, after the notorious Oct. 17 afternoon so packed with violent, concussive hits that it became known as Black Sunday, the NFL announced it would stringently enforce rules against head shots. That clouded Brown's mind. "I tried to break down and then come up," says Brown of the play on Edwards. "He dipped his shoulder, and that got him lower than me, and I took the brunt of the hit. They talk about defenseless receivers. I put myself in a defenseless position, and I hurt my shoulder. I was confused with all the changes, and I made an adjustment." (Though his forward momentum was stopped, Edwards never did go down—four other Cleveland defenders threw themselves into the play, and the whistle blew with the Jets receiver still standing.)

Brown is sitting on a shaded bench outside the team's headquarters in Berea, Ohio, after a morning practice during training camp. He covers receivers for a living, but he makes tackles, too, and it's much too late to change his approach. "Not trying to be dirty, but I've got to play the game the way I've always played it," he says. "I've got to run through tackles. If [league officials] punish me, they punish me."

For a very long time, coaches at all levels taught players to tackle with their shoulders. "It goes all the way back to playing the game without face masks [which entered the NFL in the mid-1950s]," says Patriots coach Bill Belichick, for whom the history of the game is an avocation. "Guys were taught to lead with their shoulder and turn their head to the side to protect their faces. Then equipment changed, and techniques changed. Players were taught to generate all their power in a straight line. Both hips, both legs. That allowed you to put your face in the middle of the runner, keeping your eyes up. It was a fundamentally better way of tackling."

http://sportsillustrated.cnn.com/vault/article/magazine/MAG1189947/index.htm 

Tim Layden wrote: