At the start of 2011, the New York Jets were considered a team to reckon with. Led by Rex Ryan, their exuberant and controversial head coach, and a young and at times erratic quarterback, Mark Sanchez, the Jets had reached the AFC championship game the two previous seasons. They were thinking Super Bowl when Ryan and Mike Tannenbaum, the Jets' general manager, invited journalist Nicholas Dawidoff to chronicle the team's fortunes. "They gave me a security code, a desk in the scouting department, a locker, and the freedom to roam," Dawidoff writes in his new book, 'Collision Low Crossers: A Year Inside the Turbulent World of NFL Football.' "Nobody in modern professional football had ever let someone like me inside before."

"Anything can happen," Tannenbaum warned Dawidoff at the beginning of the year. "Things can go very badly." And they did. By November, the midpoint of the 2011 campaign, the Jets had gone a shaky 5-3, largely due to the poor play of Sanchez and the rest of the anemic offense. The defense, one of the league's best, kept them in most games, but the players and coaches had begun to resent their underperforming teammates on the other side of the ball. Fissures had begun to reveal themselves in the team's unity, doubts about Sanchez continued to surface, and now they were facing crucial back-to-back games, the first against the archrival New England Patriots, followed by the Tim Tebow-led Denver Broncos.

Tuesday was the players' day off and the longest day for the coaches. For most of the morning and afternoon, defensive coordinator Mike Pettine and offensive coordinator Brian "Schotty" Schottenheimer would "slow cook" their game plans, as Pettine put it. During football season, every night all over America, sleeping badly on office couches, are overweight middle-aged coaches with broken marriages. Rex Ryan was typically gone by 11 p.m. Pettine slept on the mattress he kept in Ryan's closet.

Some people question why football coaches put in such hours, but a game plan is their creative work. Coaches say that even on the best professional teams, only 10 percent of the time do all 11 players perform their roles as scripted. But you always aimed for better.

Besides, the mere idea of free time is for them anathema – they feared not working, because working all the time was the only salve for the anxiety-driven nature of the job. In August, with Hurricane Irene bearing down on New York, a Jets preseason game against the Giants had been postponed. The coaches and players were told that they should stay home, and that their practice facility in Florham Park, New Jersey, would be locked and all entry pass codes deactivated. Some of the offensive coaches began plotting to go straight to Florham Park ahead of the storm and stay there, locked in through the hurricane, bedding down under their desks.

"All right, men, Patriot week," Schotty began at the Wednesday-morning quarterbacks meeting. He said he would first show them some film before detailing his game plan for New England because "[you] gotta learn to swim before you go into deep water."

"What about swimmies?" asked Mark Sanchez. The man was loose. At times, so was his play.

Upon taking the Jets job two years earlier, Ryan had no viable starting quarterback, and to his eyes, Sanchez was the best one available. The Jets dealt three players and two draft choices to the Browns in exchange for the fifth choice in the 2009 draft, and Sanchez arrived in New Jersey to sign the most lucrative contract in franchise history. The Jets quickly made Sanchez their starter, and in his first two seasons he led them to the AFC championship game – or perhaps they led him. In Sanchez's young career, the Jets had carefully protected "the Sanchise," emphasizing his virtues, limiting his playbook, minimizing his job competition, posting a media-relations staffer by his locker whenever he gave interviews. While he flashed the potential of someday becoming the polished, dynamic professional Ryan foresaw, he was still erratic, and so mostly he was a restricted element in a conservative run-first offense stocked with able veterans who gradually, over the course of the game, wore down the opposing defense. That the Jets still had no clear idea how good a quarterback Sanchez would become was nothing surprising; it pointed again to the difficulty in predicting the futures of football players and was part of the game's mystery.

So I felt for Schottenheimer. He had a young quarterback who wasn't much better than during his rookie year. He also had three temperamental playmaking veteran receivers in Plaxico Burress, Derrick Mason, and Santonio Holmes, who all wanted the ball – a good thing, except that if Schotty played them all, as Ryan had asked him to, that meant fewer running plays and also no extra lineman to buttress his injured line. That line was a broken fence, meaning you couldn't throw deep, and if the defense knew that there was no risk of verticals, they cheated on short-route coverage. So now the receivers were feeling resentful.

It was the opposite in the offensive meeting rooms up in New England. Tom Brady was an easy man for an opponent to dislike. He seemed to have it all: talent, success, good looks, a supermodel wife, and those big eyes rolling petulantly skyward whenever things didn't go precisely his way. So pretty and so good – how could you not want to knock him around? But that was not easy to do. Peering across the line, Brady was a defense analyst; his release was rapid and sure, making even mediocre NFL offensive linemen seem staunch, and his arm was strong and accurate. The coaches all looked forward to the challenge of trying to beat Brady as well as his coach. In an era of parity, Bill Belichick was the only NFL coach who won consistently, year after year. Around the league, people talked about him as the ur-coach, the impossible model.

Ryan, who lived for big games, walked into the team meeting and approached his lectern with purpose. He carried a wooden baseball bat roughly the size of a loblolly pine. "Bring your bat!" he told the team. "This is the game! They're pissed off. We're pissed off." Everything about Ryan was big. His voice – flat, stentorian, tinged with the one-horse-Oklahoma inflections of his forebears – was an instrument whose design predated the age of microphones. Standing beneath the media kliegs, which emphasized the astonishing whiteness of his teeth, the smooth flush of his face, the convexity of his configuration, Ryan brought to mind a Coca-Cola Belt politician planted atop the back of a flatbed truck, suit jacket flung at his feet, imparting jubilant election-week promises to the little guy.

"You want to know how to be successful in a big game?" Ryan continued. "It's all preparation. Do the little things." Bob Sutton, the linebackers' coach, leaned toward me and whispered, "Both teams will be ready. One team will be prepared." Then Ryan said, "Both teams will be ready. One team will be prepared." Sutton grinned. "I'm telepathic," he said. (Sutton occasionally helped the boss with his speechwriting.) "This," Ryan concluded, "is a bring-your-bat game." (The flourishes were all Ryan.)

At the defensive meeting, Pettine said all he cared about was that his unit played fast, physical football. How had the Steelers defeated the Patriots two weeks ago? "It was violent," Pettine said. "Physicality is not something you just turn on come Sunday." To many, Mike Pettine was a man of mysterious, complicated passions – the dark order complementing Ryan's joyful chaos. In Baltimore, he had been Ryan's protégé, and the two had worked so well together over the years, planning the Ravens defense, that they had become "brothers," as Ryan put it. The past two years in New York, the Jets defense had been either the best in the league or just about.

He was methodical as he reviewed the calls, explaining not only what he wanted but also each call's relationship to previous iterations. Everything was a version of something they knew well. A few calls he'd been saving for weeks. One had been created for the first New England game but never used; there'd been a pre-snap penalty, after which Pettine changed the look. He peppered his descriptions with what the players' thoughts would be: "David asks, 'Whose helmet can I knock off? Whose ribs can I damage?'"

Later that day, Darrelle Revis and the other starting cornerback, Antonio Cromartie, were reviewing the Patriots film together. They were as struck as Pettine was by the contrast between Brady under pressure and Brady with excellent protection. Brady had, Cromartie thought, "that nervousness in him." Most quarterbacks did. It was just that Brady was usually so icily poised that the vulnerability in him was more striking when you saw it.

On film, Cromartie said, the Patriots were doing "the same thing over and over. It's not even different formations. It's just different personnel groups. The exact same thing with different people running it." He compared the Patriots offense to his own. "This is what makes them so good. They put everybody in the quarterback's vision. He can see where everybody's gonna be. Our offense, if they run two posts, they run the other guy coming back. Mark can't see him – it's not in his vision."

On the Jets, where the defense was not only tough but original, there was the growing feeling that Schottenheimer and his offensive players were holding the team back from winning a championship. The previous year, the Jets had begun their season with a game against the Ravens and lost, 10-9. The Jets offense was one for 11 on third down and secured a franchise-low six first downs. The game had been personal to the former Ravens coaches on the defense, and before it they had given Schottenheimer many suggestions regarding the Ravens players they used to coach. None were taken. Afterward, Pettine was so upset he could barely speak. "We knew them," he kept repeating.

The defense's superior attitude, Pettine knew, "chaps some asses across the hall," but this was the way football teams worked. He liked Schottenheimer, considered him "a great, great guy," and he knew that with a young, shaky quarterback and such an accomplished defense, "Schotty's in a tough spot." If Pettine had been the head coach, he would have sought Schotty out, tried to help. Pettine hoped someday to be a head coach. But now he was the defensive coordinator, and "I never want to farm somebody else's land. That's how you get in trouble."

At practice, although Sanchez shouted "Boom!" each time he completed a pass, and although Revis made three interceptions, the play was generally ragged. Why? Nobody could say. It was one of the cryptic aspects of the sport: Good practices could not be willed. Afterward, with the team circled around him at midfield, Ryan was as angry as I had ever seen him. Usually he preached the need for balance in the players' life. Not now. He spoke a philippic about "nothing, I mean nothing, in your life this week" being more important "than this game."

At the team hotel on Saturday night, in the 7:45 quarterbacks meeting, Sanchez was reading from the big and colorful call sheet like someone happily perusing a bistro menu. With his dark, curly hair, sloe eyes, beauty marks, and pouty mouth, Sanchez could have been a leading man in a movie. Being that good-looking, Sanchez was initially a startling presence in any room he happened to be in, but he settled everyone down with his good nature. He was a carefree Californian who called most people "dude" and saw the world optimistically: There was little in life that wasn't "sweet!" or "sick!"

The day before, he had mentioned how every Thursday night he went by himself to a local restaurant to eat a late dinner and study the flash cards he always made to memorize the week's game plan. That night, the waitress had come to take his order just as Sanchez flipped to a new card and discovered that – oh, no! – somebody had slipped in a card decorated with an enormous red dong.

Schotty asked Sanchez if a particular call confused him. A similar call, the coordinator said, had given the quarterback problems against Miami. Suddenly Sanchez looked like he'd eaten a bad snail, as he frowned and reflexively told Schotty, "I messed that up."

The receivers arrived, and Schotty told everyone, "Sooner or later they'll get tired of giving up those 8- or 9-yard routes, and then you can go deep." As he spoke, Sanchez made a succession of funny faces and finally said, "Unnhh!" When the others gazed at him curiously, he said, "Just getting excited!"

Everyone handles football pressure in his own way.

The game didn't start well, and almost immediately after the kickoff, in the coaches' box, Mike Tannenbaum, the Jets general manager, was upset. He didn't like the way the receivers came out of huddle, their body language betraying run (they'd seem disinterested) or pass (there'd be a bounce in their step). "It's obvious to me!" Given the many injuries in the Patriots secondary and the low number of Jets completions, one could almost understand Tannenbaum's frustration.

The defense's plans for matchup substitutions were being thwarted by the Patriots shift to a no-huddle, hurry-up offense in which Brady lined up his offense again at scrimmage right after the tackle and shouted out his coded instructions from under center. He ran play after play so quickly, the crowd couldn't even organize a roar to drown out his voice. "Look at the pressure no-huddle puts on opponents," said Tannenbaum. "Shouldn't we do that to them?" Still, despite the Jets offense's latest slow start, the Jets were in excellent position because the defense had given up only two field goals and then harassed Brady into a safety. Near the end of the half, Sanchez led a touchdown drive. Unfortunately, he had called a time-out right before the score, stopping the clock and leaving Brady and the Patriots 80 seconds – enough time for them to traverse the entire field and retaliate. With nine seconds left in the half, New England regained the lead, 13-9.

Tannenbaum had pointed out to me that in recent years in the NFL, anywhere from half to three-quarters of the games had been decided by one score. And sheathed right there in that cold, blunt statistic was the murmuring anxiety of every team's predicament: The NFL had achieved such a level of parity that a form of competitive entropy existed. In any given game, either team could win. Tannenbaum, and the coaches, were in command of what they could not control; and so it was their job to be responsible for the irresponsibility of others. When Cromartie fled north as his man went south and west for a huge play, it was ultimately on them. Nobody on the Jets could cover the hulking New England end Rob Gronkowski, and that redounded to them as well. There were several other people in the box besides Tannenbaum and me, and at halftime, a couple of them shook their heads and quietly seemed to doubt that the team could win games like this with Sanchez.

The Jets defense played well for a while in the second half, but gradually they tired and the score became 23-9. When the offense scored to make it close, the Patriots then took it "84 yards right down our throat," as Tannenbaum said. After Sanchez threw a denouement interception that was returned for six more points, to make the final score 37-16, Tannenbaum, thinking about defensive rosters, asked, "How can they be out there with 37 points with the players we have and we have 16 points and the players they have? Can anybody explain this?"

The morning after any loss, the facility was a desolate place. The wide hallways were like downtown streets in a Rust Belt city, the loss pervading in such a strong way that I half-expected to confront fallen trees, broken windows, overturned garbage cans, wrack-strewn puddles. Football people often talked of big losses feeling like deaths, and the requisite periods of mourning had to follow. The losses were excruciating because they always seemed to come as a surprise. The game had been successfully played and replayed so many times on paper before the spectacular high of kickoff that the disappointing realness was a steep dive. "You can remember every loss" is what Rex Ryan, perhaps the most optimistic man I have ever known, told me. "I can tell you what happened. I can't do that with wins. Look at all the time you lost with your children. You never get it back. You have to win, or it's not worth it."

The way they moved past the great pain was by seeking a formal understanding. All around the building, they gathered in groups to watch the film, to ask themselves if Sanchez could learn to read the coverages more astutely, to ask if he could get through his progressions faster. Figuring into all this was the knowledge that there was a difference between moving on and forgetting.

In a late-Monday-afternoon team meeting, Ryan said he couldn't lie to the Jets. They probably wouldn't win their division. There was much else to play for, he said, and then he placed a chip of wood on their shoulders and knocked it off. Had they heard what happened after the game? Walking off the field, Belichick had turned to his son and said, "Thirty-seven points on the best defense in football, suck my dick." In his meeting-room seat, Revis was horrified. "I think that's a jerk," he said to me later. "Maybe some people think he's a good, collected guy off the field, but then why say such things? It's degrading. Suck my what? Say it to my face. That's not great character."

The fact remained that the Jets had lost, so what could Revis do except look to the next opponent, another difficult game. They'd play against Denver and Tim Tebow, the former college phenomenon who was now a portent of NFL things to come, a starting quarterback who won games by running. To Pettine, the Broncos represented about as abrupt a stylistic shift from the Patriots as he could imagine. He compared moving from Brady to Tebow to transitioning from a Ferrari to a truck.

Part of the challenge was scheduling. NFL teams hate playing Sunday-night games. Football men are up-in-the-morning people, and here you had to wait all day, and then, even if you were the home team, you didn't get to bed before two. If you were on the road, it was a missed night of sleep. Thursday-night games were loathed even more than Sunday-night ones. There was insufficient time for physical recovery from the beatings of the previous game and insufficient planning time for the next one. To play on Thursday night after playing Sunday night, with, moreover, the second game on the road, and at altitude, was tearing out the sutures before the wound was healed.

Given the brief interval at the facility between games, not quite three days because of the long flight to Colorado, triage would be in order. Opposing Tebow required extra rehearsal, meaning there would be no two-minute-drill practice for the defense, and that would prove costly.

Professional football players prepare so obsessively for each game that they often don't know the names of the players on a future opponent's team until the week before the game. As one of the Jets put it about an opposing player, "He's just a number. Who gives a fuck who they are as long as we do what we're supposed to do?" Because Tebow had been, until recently, a reserve NFL player famous for his college career and his religious good works, he was a football specter to most Jets.

Greg McElroy, Sanchez's backup, had opposed Tebow in college. Talking on Monday afternoon, he recalled the Alabama defensive game plan against Florida. The Alabama coaches didn't think Tebow read defenses well, McElroy said, so they showed Tebow complex looks and created a pass rush that emphasized containment rather than their usual high-pressure dashes toward the quarterback. That was because Tebow's most devastating skill was his ability to circumvent blitzers, creating drive-bys, pass rushers skidding past as he went thundering downfield.

Although this was Tuesday, the players' day off, it was a short week, so they had a full day of classroom work and practice. At the morning defensive meeting, Pettine further introduced Tebow to a roomful of yawning men clutching coffee cups and spit bottles for dip. Tebow, Pettine said, was streaky, unpredictable, and a winner. As a passer, he threw three in the dirt and then, the coordinator said, he threw "a laser beam on the money." When he ran, he broke tackles, was deceptively fast. The idea was to force him to make quick decisions. "He can make you miss," Pettine warned. "Bit of a Houdini."

Everyone seemed still exhausted from the Patriots game as they headed out to practice. It was a cool New Jersey fall day with a high slate-blue sky and soft breezes, yet somehow it seemed overcast, with so many people walking around dog-faced and hurt. Revis, his knee sore and braced, was glum. It was at times like this that Ryan shone. During his first season with the Jets, the team had at one point lost six out of seven games. The Jets players expected retribution. Instead, one afternoon Ryan promenaded through the locker room wearing only a black vest. Here he was everywhere, telling jokes, relating anecdotes to lighten the mood, bucking people up. When Plaxico Burress, the receiver, made like a tollbooth gate, raising his long arm improbably high to snag a pass, everyone yelled, "Whooooaaah!" Last week at this time it had seemed reasonable to talk about the Super Bowl. One loss had thrown all into doubt.

After practice, Revis and Cromartie watched film of Tebow, observing with incredulity the length of time it took him to wind up and release his passes and the frequent inaccuracy of those throws. "I don't understand it, man!" Cromartie said. On the screen, balls were spraying everywhere. "That's crazy."

The Jets planned to run and expected the Broncos to do the same. Runs didn't stop the clock the way incomplete passes did, leading Sanchez to say on Wednesday morning in the quarterbacks meeting, "Men, this game's gonna take, like, 20 minutes." For the rest of the meeting, the quarterback continued to employ stock Schottyisms. Everyone was addressed as "men," and many things were prefaced with "the ole," which was, in fact, a Rexism appropriated by Schotty. Schotty, in turn, was referring to Sanchez as Coach. Looking at me, Schotty said, "Nick, we're dealing with maturity issues this side of the room!" It was the only time all year he voiced aloud something I was sure often ran through his mind.

In the Wednesday team meeting, Ryan told the players, "Be comfortable on the plane. No suits unless that's you!" Most chose to fly in sweatsuits, some in sweatsuits of Baskin-Robbins colors. To his defense, Pettine stressed that in a short week, nobody knew what the other team would allocate time to prepare for and that all football teams felt vulnerable when they believed they were underprepared. It would be good to worry the Broncos in that way early. "Give them conflicting looks," Pettine said. "Move around. Make them think." In Colorado that evening, at the quarterbacks meeting, the players discussed Tebow's propensity to sail balls toward the stands and nose-cone them into the dirt. Like Cro, they'd never seen anything like it in an NFL starter. Sanchez, wearing a gray fur hat, was looking exhausted, and Schotty treated him with particular solicitude, telling him, "You're doing a really good job with a lot of stuff." The coordinator urged Sanchez, "Say uncle! Protect the ball and move on with your life." It was not a game in which to try anything rash, Schotty said. "Just get points. They're at a premium because I don't think they score on our defense."

In Denver, on the bus to the stadium, there was a faint odor of anxiety. Well before we reached it, the stadium was visible in the distance, a big shimmering new-world building. Out on the field before the game, Tebow soared errant practice throws so far and high, I kept noticing the downtown skyline. Up in the coaching booth, Pettine sat silent with his multitude of pens and markers, then he fist-knocked with the other coaches before kickoff. Early on, Pettine kept careful track of the positioning of the edges and his deep safety. "I can't stress it enough, edge guys, don't chase until you see the QB give up the ball," he said into his microphone.

The game involved much punting. The Jets defense often was left to work from poor field position; five Broncos possessions started from the Jets side of the 50. On these possessions, the Jets held Denver to only three points. The Denver backs were having no success, Tebow wasn't running much, and Cro had been right: The quarterback's big windup brought to mind a gantry crane boom as he swiveled before he threw. Pettine was on his game. "Watch the screen," he'd call, and it would be a bubble screen. Schotty and Sanchez were having less success. "Unbelievable," said Pettine after every drive-killing offensive penalty or run for a loss. The offensive coaches seated to Pettine's left were very quiet. When Sanchez imprudently burned a time-out, one of them muttered, "Schotty might kill him." The Jets got the defensive formation they wanted for a 38 Special – reborn! – direct snap to running back Joe McKnight, but the ball rocketed way over his head. "Un-fucking-believable," said Pettine.

Suddenly, in the third quarter, the offense was at the Denver 1-yard line. Pettine was begging, "Please don't fuck this up." Bilal Powell fumbled into the end zone, and lineman Matt Slauson recovered for the touchdown. "Un-fucking-believable." Pettine sighed. "Line drive in the box score," said one of his assistant coaches, eyes front. The Jets led 10-3.

Pettine played personnel chess with the Broncos, sending one group out a few steps and then withdrawing them: "I want to go big sub – not yet!" Denver changed to a running set. "We've got big people in. We're OK." Tebow heaved a pass that appeared bound for a snowdrift outside Aspen. "Oh!" cried the coaching box in wonder. But it was Sanchez who made the crucial mistake. On a third and six, instead of saying uncle, he threw an interception that was returned for a game-tying touchdown. "Fuck me!" roared Pettine. "And he's got Joe McKnight one-on-one with the linebacker."

They had contained Tebow so far, but as the third quarter ended, Pettine asked Ryan, "Want to heat him up, Rex? Just asking." Instead they went with extra coverage. A nifty one-handed catch by Joe McKnight led to a Jets field goal, making the score 13-10 in the Jets' favor with nine minutes and 14 seconds left. Then the defense stuffed the Broncos on third and two. "Let's go up two scores," said Pettine hopefully. But the offense stalled, and was forced to punt, pushing the Broncos to their own 5-yard line. To this point, eight of the 11 Broncos possessions had lasted three plays. On their third downs, the Broncos were one for 11. Tebow had run twice for 11 yards. Passing, he was six for 15. It was difficult to imagine any team playing better defense on short rest than the Jets were. There were five minutes and 54 seconds left. "All we got to do is keep the edge," said Pettine. They couldn't. Tebow began dropping back and either completing passes or working the dog-and-tennis-ball. "Tell these guys to stop flying by the quarterback," Pettine cried. Tebow had become a football Sherman, leading an inexorable march. Into Jets territory he went, the crowd chanting his name.

With the Broncos across the Jets' 30, again Pettine considered the blitz, which he had yet to show. "At some point we got to come after him. Is now the time?" At third and four at the 20, with three Bronco wideouts in formation and nothing else showing signs of stopping the Broncos, Pettine asked Ryan, "Want to come after him, Rex?" Ryan did. The call was Comcast, meaning the safety was to blitz. He charged, Tebow eluded him, and with the edge now uncontained, the Colorado plains opened up vast and unpopulated. In the end zone Cro lingered behind Bronco receivers as Tebow heavy-hoofed toward the goal line for the lead.

The game ended at 17-13, Broncos. Tebow sank to a knee as up in the booth Pettine said, "Oh, this is a kick in the nuts, boys." In the locker room, Schotty was slumped, speechless. "Job's not for the faint of heart," he told me later. Ryan looked at his players, who had just lost twice in four days, and spoke them a threnody: "It stings. It hurts. I believe in this team. Am I the only guy who believes in this team?"