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WITH EACH STEP, the crowd swells. Three, four and five deep they stand, dressed in blue and gold with blots of green. They line the sidewalks and rise up on their tiptoes to catch a glimpse of the Fighting Irish, moving en masse toward Notre Dame Stadium. It's the first Saturday in September. Week 1. And two hours from now, Notre Dame will host Texas under the lights, the first meeting between the college football blue bloods in 19 years.

In the middle of it all, guiding the Irish offense, will be Mike Sanford, the hottest young coordinator in the game. It was March 2 when head coach Brian Kelly officially introduced the 33-year-old he had hired away from Boise State to re-energize the playbook, improve the inconsistent quarterback play and help lead the program to its first national title in nearly three decades. Lucky for Kelly, the kid knows all too well the pressures of coaching in South Bend -- his dad, also named Mike, was the Irish quarterbacks coach in 1997 and '98. Young Mike, he was a ball boy. Until today, he had never even seen the Notre Dame players' walk, only heard about the pageantry from his father.

With cheers and the late-summer sun beating down on him, Sanford tries his best not to let his mind drift to the task ahead. After all, he has no idea what to expect. "Any coach who tells you he does before the first game is lying," Sanford says. This walk -- from Hesburgh library past Touchdown Jesus to the stadium's Knute Rockne gate -- is one to savor. For now, life is good. His quarterbacks have yet to throw a pass, much less a pick. Adversity has yet to strike. He knows it's inevitable. Somewhere down the line, another moving truck awaits. The only question is whether or not it will be his decision to leave town or someone else's. That fate lies in the hands (and the health) of guys in their late teens and early 20s. One costly mistake, one unlucky injury and it all could change.

When Sanford arrived, he was already in the middle of a quarterback duel between redshirt sophomore Malik Zaire and redshirt senior Everett Golson. Zaire had taken the starting job from Golson just two months earlier, rushing for as many yards (96) as he passed in an MVP-winning performance in a 31-28 Music City Bowl victory over LSU. Golson, who led ND to an undefeated 2012 regular season and the BCS title game before missing 2013 due to academic issues, had fallen out of favor with Kelly following 22 turnovers in 2014, when he lost five of his last six starts.

While Zaire and Golson split snaps during the spring, redshirt freshman DeShone Kizer, whom Sanford described as "a little heavy," struggled with the limited reps of a third-stringer. He was also understandably distracted by the health of his girlfriend, who had a baseball-size tumor removed from her neck during a 17-hour surgery in April. In the Blue-Gold game, Kizer was just 1-for-5 for 3 yards and was sacked once. Afterward he texted Sanford: "In order to be great you have to hit rock bottom. And that game for me was rock bottom."

But despite the shaky performance, Kizer quickly rose up the depth chart; Golson, upon graduating in May, bolted for Florida State before a starter was declared. The bombshell transfer eliminated controversy, but it amplified the need for Sanford to expand Zaire's run-heavy repertoire and prepare Kizer, who was now an injury away from being the starting QB at Notre Dame.

Outside the Guglielmino Athletics Complex, quarterback became the biggest question mark for a team that, on paper, was considered Kelly's most talented in six seasons. Inside, Sanford began to do what he does best: build a bond with QBs. The group grew close, which is exactly how Sanford wanted it. In a preseason goals meeting, Zaire told the coach he wanted to win the Maxwell Award and lead ND to a national title. If he did both, he figured he'd probably win the Heisman too.

Meanwhile, Kizer showed up for fall camp with a retooled body. At 6-foot-4, 230 pounds, he was quicker, more agile. Sanford often made Kizer "live" in practice to further acclimate him to the physicality of big-time college football. Even though Sanford was hyperfocused on preparing Zaire for the season, he kept an eye on Kizer as well, singling him out in QB meetings as if he were the starter.

"I tried to put him in that hot seat," Sanford says.

Sanford left his alma mater Boise State for the big time after just one season. Matt Cashore/USA TODAY Sports

A FEW DAYS before Texas came to South Bend, Kelly stood behind the lectern at his weekly news conference and attempted to explain the effect Sanford has had on the program. For Kelly, the move was more than outside-the-box thinking. It was unprecedented. In 25 years of head coaching, from Grand Valley State to Central Michigan to Cincinnati to Notre Dame, Kelly had never hired an offensive coordinator who hadn't worked with him previously. So why Sanford, who is his fourth in six seasons?

In one year as the offensive coordinator at Boise State, where he himself had been a backup QB, Sanford engineered the nation's No. 9 scoring offense and coached the nation's most accurate passer, senior Grant Hedrick (70.8 percent). The Broncos finished 12-2, culminating in a 38-30 Fiesta Bowl win over Arizona. After a single season as an FBS offensive coordinator, Sanford reportedly drew interest from Vanderbilt, Oregon State and even defending national champion Ohio State. But he didn't truly consider leaving Boise until Notre Dame called.

Sanford's bond with Kelly had been formed in early February, during a four-hour chalkboard session in the library of a cushy resort in Park City, Utah, where both men's families were coincidentally vacationing after signing day. They instantly hit it off in a skull session Sanford describes as intellectually stimulating. Kelly insisted that if Sanford came to South Bend, egos would not get in the way, that he, Sanford and associate head coach Mike Denbrock would collaborate to build the best offense in the country.

"It's natural when you run a system like I have for over 25 years that you become accustomed to doing things a certain way," Kelly said at the Texas game-week news conference. "When you get the question, 'Why do you do it that way?' then you have to answer honestly. That kind of turns it upside down a little bit. That's been good. It's been refreshing."

That the baby-faced Sanford is able to challenge Kelly's hard-line approach speaks to his strength at building relationships with coaches and players. Long before he realized he wanted to follow in his father's footsteps, Sanford often tagged along to practices at USC, where his dad was wide receivers coach from 1989 to '96. It became perfectly normal for Sanford to play pickup hoops with Keyshawn Johnson. When his dad coached receivers for the Chargers from 1999 to 2001, it was Sanford's job to warm up QB Jim Harbaugh. He witnessed firsthand the importance of treating players firmly but fairly and also learned how fleeting each coaching gig could be.

Sanford (left) was a student of his father's game. Courtesy Sanford Family

When Sanford was in fifth grade, with USC struggling to a 6-5-1 season, his Spanish teacher called his dad and mom, Melinda, to inform them that the stress was affecting their son in school.

"That was the hardest time for me in terms of being a kid in this profession," says Sanford. "If we lost, I'd get ridiculed on Monday, and I would get fiery with people. For them, it's just a game. For us, it's where we live. It's my dad's employment. I'm still that way. This isn't a fun little tailgate party. This is our life."

But perhaps the most difficult lesson Sanford learned -- how to handle quarterbacks -- came during his own playing days. As a junior at Penn High School, outside South Bend, he worked tirelessly to be QB1. The job went to someone else. Instead of sulking, Sanford took the opportunity to better his game in practice and observe from the sidelines before returning to California when his dad was hired by the Chargers. He played well enough as a senior at Los Alamitos High to sign with Boise State, where he was eventually passed over again as a senior in 2004, when then-head coach Dan Hawkins anointed sophomore Jared Zabransky the starter.

"He was devastated," says Sanford's father, who is now the head coach at Indiana State, three and a half hours south of ND. "But he had seen through the course of my career those kinds of decisions. So we just encouraged him to be a great teammate."

Sanford spent most of the season holding a clipboard and wearing a headset, serving as a conduit between Zabransky and offensive coordinator Chris Petersen. "I've listed that season on my résumé as my first year of coaching," Sanford says. After earning a degree in political science and spending two years as a graduate assistant under his father at UNLV, Sanford received his first big break from a familiar face.

Sanford (left) received his first coaching break from Harbaugh, the QB he'd helped warm up when his father was the Chargers' WRs coach. Courtesy Sanford Family

When Harbaugh was hired as the head coach at Stanford in 2006, Sanford borrowed money from his father to fly from Las Vegas to San Jose for the news conference in Palo Alto, planning to make a cold pitch. By pure coincidence, he sat next to Harbaugh on the flight. Before the plane even landed, Sanford had all but secured a spot as an offensive assistant. Following one-year stops as an assistant at Yale and Western Kentucky, Sanford returned to Stanford in 2011 under new head coach David Shaw, who hired him to coach running backs, promoting him to QBs after two seasons.

"He really understands staff dynamics and is very personable," says Shaw, who will face his former assistant when the Irish travel to Stanford in the final week of the season. "I'm always going to root for him. Not necessarily when we play him. But he's a good person and a good friend."

Last season at Boise State, Sanford proved just how valuable he'd become. Five games into the season, after Hedrick threw four picks in a 28-14 loss to Air Force, Sanford and head coach Bryan Harsin warned the senior he was in danger of losing his job. As they left the closed-door meeting, Sanford patted his QB on the back. "He said, 'Let's go, man,'" says Hedrick. "It was something so small, but it just told me that he still believed in me. That simple pat -- that's all it took." Hedrick threw only five more picks in nine straight wins.

The coaches and players who've been a part of Sanford's rise say there are no revolutionary schemes or never-before-seen trick plays. He has an innate talent for relating to his quarterbacks -- and calling the perfect play at the perfect time. But does that same uncanny decision-making apply to his latest career move? To leave behind his alma mater (and a potential chance to be Harsin's successor) after just one season for one of the most pressure-filled coordinator jobs in the country?

Just a week after Sanford aced his first test against Texas, his starting QB went down for the season. Andrew Shurtleff/AP Images

IN THE OPENER against Texas, Zaire went from a question mark to a Heisman candidate. He shredded the Longhorns' secondary, completing 19 of 22 passes for 313 yards and three touchdowns. He spread the ball to seven different receivers, and his 86.4 percent completion rate was the second highest in school history. A 38-3 lead allowed Sanford to insert Kizer early in the fourth quarter. On his only pass attempt, Kizer targeted an open receiver but threw the ball into the dirt. Afterward, he confessed to Sanford that he was aiming instead of just throwing. "Next time I'm going to cut it loose and play fast," he said. No one could have fathomed how soon next time would come.

Just one week later, with ND leading at Virginia 19-14 late in the third quarter, Zaire took a shotgun snap from center Nick Martin and barreled to the left. As UVa defensive tackle Trent Corney was pulling Zaire to the ground, safety Kelvin Rainey assisted on the tackle and landed awkwardly on Zaire's right ankle. It snapped. X-rays would later confirm his day and his season were done. The team now belonged to Kizer.

On his first play under center, Kizer handed the ball to running back C.J. Prosise, who scampered 24 yards for a touchdown and a 26-14 lead. Earlier in the game, on a fake field goal, Kizer had shoveled a pass to tight end Durham Smythe for a touchdown. So when Kizer returned to the sideline following the Prosise score and put on the headset, Sanford cracked a joke to ease the nerves. "I told him, 'All we do is score touchdowns when you're in the game,'" Sanford recalls. "He got a good chuckle out of that. I just wanted to loosen him up a bit."

Even with a new quarterback, Sanford, Denbrock and Kelly refused to alter their game plan. "Let the kid play," Kelly told his assistants over the headset. But UVa took advantage of the uncertainty, scoring two fourth-quarter touchdowns after stopping Kizer twice -- including a three-and-out -- to go up 27-26 with just under two minutes remaining. That's when Kizer relayed his own message to Sanford up in the press box: "Coach, we're going to go win this game right now."

"And he said it in a way that the conviction was sincere," Sanford says. "I've been around backups who say something like that, but you can hear that flutter in their voice. With DeShone, there was no flutter whatsoever. He meant it."

Facing a fourth-and-2 from his own 28, Kizer ran for 4 yards to keep the drive alive. With 20 seconds left and the Irish just outside field goal range, Sanford, Kelly and Denbrock agreed it was time to take their shot. Throughout the game, the coaches had noticed the Cavaliers were all over slant routes. And with a first-time quarterback, the UVa coaches likely assumed ND would stay conservative and play for the winning field goal. Instead, Kelly & Co. dialed up a play for receiver Will Fuller to run a double-move slant-and-go.

But when the ball was snapped, Fuller was still looking to the sideline to make sure he was off the ball. Kizer recognized the hitch in timing. After taking the snap, he sidestepped a defender to buy back that second and lofted a rainbow directly into Fuller's outstretched arms. Touchdown. With only 12 seconds on the clock, the play went down as the latest in regulation that an Irish QB has thrown a game-winning score since Joe Montana connected with Kris Haines as time expired and the made extra point beat Houston in the '79 Cotton Bowl.

ND's shot at its first national title in nearly three decades is now on Kizer's shoulders. Geoff Burke/USA TODAY Sports

"In that moment, [DeShone] was playing the game and not just being a robot," Sanford says. "A robotic QB takes his drop and throws to the spot. Will wouldn't have been there. What I love is he grew up in front of our eyes in a big moment. Was it perfect? Not even close. Is there a lot to be desired? Absolutely. But it was a great start."

Minutes later in the visitors locker room, no one quite knew how to act. The national championship run was still alive, but Zaire's season was over.

"He took it as hard as any player I've been around," says Sanford. "He was wailing. He's just such a competitive kid. He wanted this so bad."

After Kelly addressed the team, he and Sanford huddled with Zaire, trying to find the words. But really, they didn't exist. Both coaches told him this was part of his journey. It would make the triumphs down the road that much sweeter. Sanford gave Zaire a hug.

Standing a few feet away, utterly conflicted, was Kizer, hurting for his teammate yet overjoyed at what he'd accomplished. Sanford approached the redshirt freshman. "We talked about preparing for this moment," Sanford says. "The way it came about? It sucks. But you can't apologize for what you just did. I can't tell you how proud I am. You showed something to your teammates and to us that we're going to need to count on down the stretch. And we will all have Malik's back in this healing process."

Sanford did his best not to show that he too was shaken by the drastic swings of the past hour. In only the second week of his first season at Notre Dame, he'd already coached one of the best quarterback performances in program history, only to watch that QB suffer a season-ending injury. Then he witnessed a game-winning touchdown bomb by a redshirt freshman with less than two quarters of college experience. He knew his next test would be preparing Kizer for a visit from No. 14 Georgia Tech and getting true freshman Brandon Wimbush, the No. 4 dual-threat QB in the Class of 2015, up to speed should the unthinkable happen to Kizer. In addition to Zaire, the ND offense has lost starting tight end Smythe and starting running back Tarean Folston for the season.

Sanford pulled out his phone and texted his wife, Anne-Marie: "So that was an interesting day at the office."

If Kizer and the offense continue to click and keep the perfect season alive, the storylines in South Bend will only get more interesting. Come next spring, Sanford might just find himself in the exact same spot as when he arrived: in the middle of a quarterback controversy.