In any given week in the NFL there are approximately 2,000 plays run from scrimmage. On each one, 22 players move in a convoluted dance of finely orchestrated chaotic violence. Within every off-tackle run and each play-action pass there are individual matchups to be won and lost and snap decisions that have to be made.

Each offensive play is carefully scripted and then broken down and diagnosed to produce a defensive counter with principles attached to every subtle movement. Even within that strict construct, the possible outcomes are limitless.

“You can practice your butt off,” former Patriots tight end Christian Fauria said. “I guarantee you something will come up that nobody thought about.” 

Such was the case when a safety from Kansas City named Bernard Pollard found himself flat on the ground after Patriots running back Sammy Morris picked him up on a blitz. With limited options available, Pollard reached out to grab something — anything. What he found in his grasp was the leg of Tom Brady.

Brady was in the process of throwing a deep pass downfield to Randy Moss, but as he was releasing the ball he found Pollard wrapped around his leg, which was now twisted into an unfortunate pretzel-like contortion.

The entire play took less than 10 seconds from snap to finish. But in those 10 seconds a cascading flood of events were set in motion that would affect not just Brady, who would miss the rest of the 2008 season with torn MCL and ACL ligaments, and the Patriots, but several other NFL franchises directly — and a few more indirectly — and alter the careers of personnel men, coaches and players around the league.

THE PLAY

It was like so many others run that Sunday. With a first- and-10 at the Kansas City 42-yard line, Brady took the snap from center and play-faked to Morris before taking a deep seven-stop drop. Everything was set in motion.

“The Patriots always teach you to know when situations are coming,” Fauria said. “It’s like swiping a credit card. All these things go on. It goes to a base, then it goes to a processor. You’re approved. You’re not approved. And it’s all happening in a matter of seconds. It’s the same thing with an NFL player.”

Pollard was coming on a blitz, and Morris was assigned to pick him up, which he did. Morris had two options available to him to deal with Pollard. He could stand him up straight, or he could go low and chop him. Morris chose the latter. He had done his job, but his method allowed for an unknown possibility.

“He put him on the ground,” Fauria said. “That’s a good block. But if you chop a guy, you know he’s going to get back up and you just hope the timing’s right. That guy got up and made the play. It happens.”

One ESPN talking head suggested that if Kevin Faulk — an acknowledged master of blitz pickup — had been in the game then Brady never would have been hurt. Message boards and online comments lit up with angry reactions to Morris’ block. However, there is no denying that Brady had ample time to sit back in the pocket and wait for Moss to come open down the right sideline.

It was an unfortunate situation for a veteran player like Morris, who after the season would win the Ed Block Courage Award, presented to one player from each team who exemplifies the principles of courage and sportsmanship and serves as an inspiration to his teammates.

Sammy Morris:

“You can take any play out there and say that something could have been done, but again, it’s the heat of the moment and it’s hard to kind of go back and second-guess every play out there.”

As Pollard was struggling to regain his balance, Brady stepped up once, then a second time, and started to deliver the familiar deep throw to Moss. Everyone knows what happened next. Pollard reached up and grabbed Brady’s plant leg, which was at that moment in a precarious position in that it was straight and unflexed.

“A lot of time with knee injuries, it’s something awkward,” Fauria said. “That same play, run a thousand times, it still might have happened once. Your fate is your fate. You have no control over it.”

While CBS play-by-play man Greg Gumbel described the action downfield, analyst Dan Dierdorf picked up on it immediately.

"Tom Brady got hit right on the knee. Kansas City came up with the ball, but that’s not the story. Tom Brady took a tremendous hit right as he released that ball right on his left leg. He was standing straight-legged."

On the official NFL play-by-play log it lists the finale as: T. Brady was injured on the play. His return is Questionable.

The same could be said of the Patriots immediate future.

In the aftermath, Moss told the press that he thought Pollard’s hit was dirty.

Bernard Pollard:

"The play was not intentional. People can call me a dirty player, you can call me whatever you want to call me, it’s not a dirty play. When you have 230 pounds on your back, and you're trying to go forward, things will happen. I saw the ball was still in his hands and I tried to get to him. I tried to get up and get to him. But I couldn't get up, so I just tried to grab him. It was not an intentional play."

In the offseason, the NFL clarified a rule that made Pollard’s lunge illegal. It quickly became known by its unofficial name: The Brady Rule.

But all that was fodder for the future and none of that mattered on Sept. 7, 2008, when Matt Cassel came on the field to replace Brady.

“When he went in,” Fauria said, “I was like, ‘Oh, they’re screwed.’ ”

He wasn’t the only one.

THE RISE OF MATT CASSEL

Career backup didn’t even begin to describe Matt Cassel, who somewhat incredibly hadn’t started a game since his senior year in high school. Cassel had the requisite prep highlights and was a touted recruit, but at USC all that did was qualify him to hold a clipboard behind Heisman Trophy winners Carson Palmer and Matt Leinart. In his career as a Trojan, Cassel threw exactly 33 passes.

The Patriots drafted him in the seventh round anyway after Cassel had impressed scouts during an offseason workout leading up to the 2005 draft. Still, most league observers assumed that meant he would get a camp invite, as his former offensive coordinator Norm Chow, then of the Tennessee Titans, planned to offer.

Chow, like everyone else, was caught off guard when the Pats made the pick. To be sure, it was a low-round, low-risk gamble and an intriguing selection at best. But entering his fourth year in the Pats system, Cassel looked no more ready to beat Washington State than an NFL team.

He cut a particularly unimposing figure in the preseason, with Brady sitting out all of the August games. Cassel had an enviable opportunity to show off all he had learned during his apprenticeship, but he failed miserably. In four games Cassel completed just 19 of 34 passes and didn’t throw a single touchdown pass. After a disastrous outing in the final exhibition game, Cassel’s spot on the roster seemed precarious.

“You don’t watch practice, so you don’t really know what you’re seeing,” said Mike Lombardi, the former NFL personnel man who now runs the National Football Post website.

“Obviously, based on his performance it didn’t look like this guy is going to be a great player. But stranger things have happened.”

With the Pats roster basically set heading into the 2008 season, all eyes were on the quarterback position as it came time for the final cut-down, and it was somewhat surprising when the Patriots didn’t acquire a veteran quarterback. And so, Cassel’s name was among the final 53 on the roster.

A commenter on boston.com summed it up for the rest of the region:

“Cassel is still on the team? Are you kidding me?”

Cassel finished the rest of the Kansas City game, a 17-10 Patriots win, and performed admirably the following week in a win over the Jets. His performance over the next three weeks was inconsistent before his breakout game against Denver, when he threw three touchdown passes and was named the AFC Player of the Week.

The roller coaster continued, but after a Week 9 loss to the Colts, Cassel found his stride and the Pats won six of their final eight games, including the last four of the regular season. On balance, Cassel’s play was a revelation and led to questions about whether it was the system that was the star, rather then the player.

“The system is good,” Fauria said. “There are a lot of good systems. He was also surrounded with a lot of talent. He got drastically better each week, but listen, if you tell a quarterback that he can throw to Randy Moss and Wes Welker, he’s going to say, ‘I can do that.’

“I wouldn’t say it’s all the system or it’s all Matt Cassel. It’s a little bit of both.” 

Lombardi agrees with that assessment.

“It’s both,” Lombardi said. “The system has to have talent, unique talent, that is driven by the system. But you also need a player, somebody who can operate the system. Therein lies the problem with trying to find the right player.”

In the offseason several people identified Cassel as the right player, and they all happened to be from the same system.

QUARTERBACK POKER

As it turned out, Cassel’s timing couldn’t have been better. He was set to become a free agent, and who wouldn’t love to have a young, and now proven, quarterback?

Recognizing an asset when they saw one, the Patriots decided to “franchise” the player rather then let him hit the open market. In practical terms, that meant they were on the hook for about $30 million worth of quarterbacks, and keeping both Brady and Cassel would have been difficult under the constraints of the salary cap.

While there was some discussion that Cassel may have been a younger, healthier and therefore more efficient investment, there was really no doubt that Brady would reclaim his job for as long as he was able. Cassel’s days in New England were now numbered.

As it happened, the Chiefs were coming off a season in which they finished 2-14. Owner Clark Hunt responded by cleaning house, kicking longtime personnel man Carl Peterson upstairs and hiring Scott Pioli away from the Patriots to run football operations for the franchise.

As he settled in with the Chiefs, Pioli was predictably uninspired by the collection of quarterbacks on his roster, and he didn’t have to look too far to find a replacement.  

When the deal went down — Cassel and Mike Vrabel to the Chiefs for a second-round pick — it was notable more for the inclusion of Vrabel then for any surprise over Cassel’s new address. But the Chiefs weren’t the only team interested in Cassel.

Josh McDaniels, the Patriots’ 33-year-old offensive coordinator, was already a hot coaching prospect when Cassel became his starting quarterback. But then McDaniels went from hot prospect to guru status.

“He’s an awful good coach, regardless of the situation,” Lombardi said. “He was always going to get a head coaching job. It was one more step in his portfolio.”

McDaniels was hired by the Broncos to replace Mike Shanahan, who had won a pair of Super Bowls in the late ’90s but was treading water throughout most of the last decade in Denver.

Shanahan had invested heavily in the care and feeding of Jay Cutler, a strong-armed, and apparently strong-willed, prospect from Vanderbilt. That patience was about to pay off. Cutler was coming off a season in which he had thrown for more than 4,500 yards and 25 touchdowns, but Cutler was Shanahan’s guy and it soon became clear that he wasn’t McDaniels’.

Cutler was upset about the trade speculation, and after a bizarre standoff, the two finally sat down to talk. It went about as well as a town hall meeting on health care reform.

Cutler told ESPN’s Chris Mortensen:

“I went in there with every intention of solving the issue, being a Bronco, moving forward as a Bronco. We weren't in there but about 20 minutes, [McDaniels] did most of the talking, and as far as I'm concerned, he made it clear he wants his own guy. He admitted he wanted Matt Cassel because he said he has raised him up from the ground as a quarterback. He said he wasn't sorry about it. He made it clear that he could still entertain trading me because, as he put it, he'll do whatever he feels is in the best interest of the organization.”

As it became clear that the marriage wouldn’t work, Cutler was finally traded to the Bears, who finally had a quarterback — something that has mostly eluded the franchise going back to the days of Sid Luckman. Thanks to Cutler’s arrival, the Bears have become a trendy Super Bowl pick and his popularity in Chicago ranks somewhere between Oprah’s and Obama’s.

McDaniels, on the other hand, has a mess. In addition to three draft picks, Denver also acquired Kyle Orton, a sort of nondescript game manager known mostly for shots of him doing shots that routinely appeared on blogs such as Deadspin. In the opening preseason game Orton was roundly booed by the home fans when he took the field.

The high stakes even reached down to Washington, where Jason Campbell found himself the subject of trade rumors involving Cutler. Campbell handled the rumors with considerably more aplomb than Cutler, but now that the cracks in the relationship are obvious, Campbell and Redskins coach Jim Zorn also opened the 2009 season under a media microscope.

“Winning always promotes this,” Lombardi said. “Scott was always going to get a job in any event. Josh McDaniels was a hot guy, obviously. The play helped Matt Cassel because it gave him an opportunity. But then it does set up a domino effect.”

NEW ENGLAND WEST

The coaching tree is a time-honored tradition in the NFL, where nothing sells better than success. While the initial branches of the Bill Belichick tree had sprouted in previous years (Eric Mangini in New York and Romeo Crennel in Cleveland), it blossomed in the 2008 offseason with Pioli and McDaniels, and even Mangini getting a second chance in Cleveland.

With so many of Belichick’s former acolytes running franchises, it’s not just quarterbacks that have been affected. The 2009 season opened with nine members of the 2008 Patriots on the rosters of the Chiefs and Broncos.

In addition to Cassel and Vrabel, the Chiefs quickly snatched up Ryan O’Callaghan and Matt Gutierrez after they had been cut by New England. Denver signed ex-Patriots LaMont Jordan, Jabar Gaffney and Lonie Paxton and traded for Russ Hochstein and Le Kevin Smith.

“Organizations like familiarity with players,” Lombardi said. “That creates a market of supply and demand. The supply of players isn’t as great as the demand because you now have more coaches who have been in that system. Most people see that as a detriment, but I think it works in the Patriots’ favor. Now when they make calls around the league saying they’re going to cut a player, if you want him you’re going to have to trade for him. You know Kansas City, Denver, Cleveland and even the Jets are going to be in line. I think it creates a better market for the Patriots.”

The market for Patriots players is high even when they don’t see a benefit. Take a player like Kevin O’Connell. By virtue of their winless 2008 season, the Detroit Lions have first crack at claiming waived players, which they did when they grabbed O’Connell after the Patriots cut him. The Lions then traded him to the Jets for a draft pick, a nice little side racket for Detroit.

The Patriots have long been one of the more active teams in the NFL trade market, and while they’ve found a willing, and accommodating, partner in Oakland’s Al Davis, they’ve also been able to work the margins of their roster collecting draft picks for players such as Hochstein and David Thomas.

THE HAND OF FATE

Imagine if you will that Bernard Pollard never comes into contact with Tom Brady’s leg. Maybe the Pats run a different play. Perhaps Morris takes a different angle on his block or Brady doesn’t step up twice in the pocket. There are, as Fauria said, a thousand different scenarios where that one play could have turned out differently.

Then what? Matt Cassel is still the guy who never started in college and who is clinging to a roster spot instead of a very wealthy man. Josh McDaniels is still the fresh-faced offensive coordinator of the Patriots waiting for his chance. Or maybe he’s somewhere else and Jay Cutler is still in Denver and the Bears are still relying on Kyle Orton. Maybe the Patriots roll back to the Super Bowl with a healthy Brady, and on and on. 

You can’t turn back the hands of time, of course, and even if you could, the people who deal in professional football don’t leave a lot of time in their day for introspection. They are trained not to dwell too deeply in whatever fortune comes their way, both good and bad. 

It’s the reason injured players make themselves scarce in the locker room and coaches around the league, not just Belichick, don’t talk about injuries. The mantras of “Next man up” and “You’re only one play away,” are not just empty clichés in the NFL, they are a survival instinct in a league that has little mercy or time for what ifs.

It all did happen, and it changed the landscape of the NFL considerably.

“If you’ve never been hurt, you don’t think about getting hurt,” Fauria said. “When you’ve had some injuries, you have to retrain yourself to get back in that mode. I came to the conclusion that there are things that I couldn’t prevent from happening to me. I also came to the realization that the faster I played, the better I was at avoiding injuries.

“But when it comes down to it, [stuff] happens.”