The relay of information begins when middle linebacker Antonio Pierce peers over to the sidelines to find Gregg Williams, the Washington Redskins' assistant head coach-defense. Williams, choosing from hundreds of possibilities, uses hand signals to send the defensive formation to Pierce.

Pierce, who acts as the defensive quarterback, gathers the other 10 defenders around him, instructs them on the set, offers a few reminders, and then the players settle into their alignment, often darting around to other positions to confuse the offense before landing where they are supposed to be. Sometimes Pierce will receive another cue from the sideline indicating an adjustment to what the offense is showing, and then hurry to the line of scrimmage to shout the new information to the linemen and check with the secondary to make sure they understand what is going on as well.

All of this takes place upwards of 70 times a game, and always within 40 seconds or less, which is the amount of time offensive teams have to begin the next play. Often, the sequence unfolds in 15 seconds or so, when opponents go to a hurry-up attack like Tampa Bay did in the second half of the opening game of the season. All the while substitutes are being hustled on and off the field.

The choreography of defensive play-calling and substitutions that unfolds between every play of an NFL game often goes unnoticed by fans. But it is vital to a defense's success, and Redskins players and coaches say it is one reason for the strong start this season by Washington's defense, which is ranked atop the NFL after two games. Besides stifling the run and conceding only one big play through the air, the defense has managed to shuffle multiple players in and out of the lineup, using more personnel than most teams, without being called for offsides or illegal procedure.

"That's why we practice," Williams said. "We practice with that pace and all that kind of stuff going in and out and it really is routine. I was teasing Antonio at practice. I don't get about halfway through the signals anymore -- I don't even get to do the whole signal -- I get about one or two movements and he just turns around and ignores me and calls it, because he's ahead.

"He knows what I'm thinking and he's a smart kid, so that helps the pace of the game."

While the nuances of executing the defensive calls transpire on game day, the preparation is ongoing. Pierce has to study hours of film to ensure he knows where all of his teammates need to be for every call. There are 20 to 30 signals he must know to get the proper formation and instructions from Williams and then set the defense accordingly.

"Our playbook is almost like an offensive playbook," Pierce said, "as far as how many calls and blitzes and coverages we have. And our practices are kind of like scripts where we go through everything that we do."

Pierce and Williams meet frequently throughout the week discussing play-calling and the tendencies of that week's opponent. Pierce must be an extension of his coach, able to take over the defense when plays transpire in a flurry and be cognizant of the various patterns the offense might call in any situation. Each practice is orchestrated at a frenzied tempo, simulating the game conditions that can make aligning the defense a difficult chore.

"It all starts during the week in practice," Pierce said. "That's when [Williams] comes and tells me what he's thinking on down and distance, what he calls and what he anticipates they're going to run. And basically when I'm calling the game I'm trying to remember all of that and you practice it so much that you kind of get used to what's going on and you watch it on film and study it to prepare. After that call comes in I take it upon myself to get us lined up and get us in the right position."

Pierce entered training camp fighting for a reserve position at all three linebacker positions but ended up the starting middle linebacker when free agent Mike Barrow injured his knee. Barrow, who might play against Dallas on Monday night, has helped Pierce adjust to his new role; Barrow played for Williams in Houston and understands his defense.

The signal exchanges between Williams and his middle linebacker quickly become commonplace, Barrow said -- "It's just reading a signal the same way pitchers do with catchers," Barrow said. "It's not that hard, you've just got to know the signals."

The middle linebacker is not just called on to get the proper information to the rest of the defense, but he also sets the tone for how the team will play. He has a very limited window to huddle, mixing points of emphasis and words of encouragement with motivational tactics. "He's very confident in the huddle," linebacker Marcus Washington said of Pierce. "And I think his confidence becomes contagious to the rest of the defense. The guys really respect A.P. for the time he puts into it and he's able to learn things so quick. You've got to take your hat off to a guy like that."

"Sometimes your instincts just take over," Pierce said, "and you just do what you need to do to get everybody lined up and get us in the best play we can be in."

There have been a few close calls, such as against the Giants last week when Williams caught the New York offense making illegal substitutions that went undetected by the officials and then countered with last-second changes of his own, leaving linebacker LaVar Arrington racing back and forth to the sideline before sprinting into position moments before the ball was snapped. Injuries during games have also complicated the implementation of Williams's defensive packages.

"You've got certain guys who play in different packages and if one of them goes down then maybe I have to stay [on the field] even if I'm not in that package," said Arrington, who will miss two to four weeks after undergoing knee surgery Thursday. "You just have to keep your eyes and ears open and be ready for having to do something that you might not normally do."

"We practice with that pace and all that kind of stuff," assistant head coach-defense Gregg Williams said about his complicated schemes.