Once his playing career ended, new USC offensive coordinator Kliff Kingsbury built a reputation as a quarterback whisperer and quickly climbed the coaching ladder.

During three stops at Houston, Texas A&M and Texas Tech, he's worked with a handful of signal-callers who found their way to the NFL. Three even heard their name called in the first round of the draft.

To be clear, Kingsbury isn't solely responsible for the development of these players. Two ended up transferring from Texas Tech.

Still, his guidance helped those two start as true freshmen. Kingsbury has a unique ability to get young talent ready to play. In nine seasons, his primary QB was either a freshman or someone who began starting when he was one.

Poor defense proved to be the downfall of his six-year tenure at Texas Tech, but scoring has never plagued Kingsbury's teams.

Case Keenum (2008-11)

Despite arriving to Houston two years after Case Keenum, Kingsbury coached the record-setting quarterback for four seasons.

Keenum started as a redshirt freshman, but he managed just 2,259 yards and 14 touchdowns with 10 interceptions through the air. He added 412 yards and nine scores on the ground.

However, the offseason brought Kevin Sumlin, Dana Holgorsen and Kingsbury to town. That trio turned Keenum into a two-time Conference USA Offensive Player of the Year—the second of which came when Kingsbury was the position coach and co-offensive coordinator.

Keenum, who is the starting quarterback for the Denver Broncos, ended his Houston career as the all-time leader in passing yards, total yards, passing touchdowns and touchdowns responsible for.

Johnny Manziel (2012)

After his successful stint at Houston, Kingsbury followed Sumlin to Texas A&M and unleashed a Heisman Trophy-winning force.

Johnny Manziel racked up 3,706 yards and 26 touchdowns through the air with 1,410 yards and 21 scores as a runner. He set a Football Bowl Subdivision record for most yards of total offense by a freshman with 5,116 and became the first freshman to win the Heisman.

That season, Kingsbury was a finalist for the Broyles Award, given annually to the top assistant coach in college football. He parlayed that success into a job as Texas Tech's head coach.

Manziel put up tremendous numbers the following season, but he didn't bring the same level of efficiency after Kingsbury's departure.

Baker Mayfield (2013)

Baker Mayfield's frustration with Kingsbury is well-documented, but no quarterback thrives as a true freshman without possessing special ability as well as a coach who knows how to properly use those skills.

A walk-on at Texas Tech, Mayfield propelled the 2013 squad to a 5-0 start while accounting for 1,607 yards and 10 touchdowns.

He ended the year with 2,315 yards and 15 total scores, then elected to transfer and cited miscommunication with the staff.

Mayfield then excelled at Oklahoma under the tutelage of Lincoln Riley, leading the Sooners to three straight Big 12 titles. The Cleveland Browns snagged Mayfield with the No. 1 overall pick of the 2018 draft.

Despite the soured relationship, Kingsbury praised Mayfield's strong arm and ability to quickly process information when NFL teams inquired about Mayfield prior to the draft, per Sports Illustrated's Robert Klemko.

Davis Webb (2013-15)

Another true freshman in 2013 fared quite well.

After the injury to Mayfield, Davis Webb announced his presence with a 415-yard effort in a victory over Iowa State. He finished the season with 2,718 yards and 20 touchdowns to nine interceptions.

Webb posted 2,539 yards and 24 scores with 13 picks the next season, though that's when the trouble at Texas Tech began.

During the eighth game of 2014—a mind-numbing 82-27 loss at TCU—a left ankle injury sidelined Webb for the remainder of the season. Patrick Mahomes took over and retained the starting job in 2015, which ultimately led to Webb's transfer.

Webb threw 37 touchdowns as a senior at Cal and was a third-round draft pick of the New York Giants in 2017.

Patrick Mahomes (2015-17)

The shining beacon of Kingsbury's tree is Patrick Mahomes, who has elevated the Kansas City Chiefs into a Super Bowl contender during his first season as a record-breaking starter.

Texas Tech needed every bit of his production to atone for a miserable defense.

Mahomes amassed 11,252 yards and 93 touchdowns to only 29 picks, adding 845 yards and 22 scores as a runner. He guided the Red Raiders to top-two marks in total offense in both 2015 and 2016. During those seasons, the offense averaged 36.9 points over 13 losses.

"He really helped my game and helped me as a person a lot," Mahomes said of Kingsbury, per Lynn Worthy of the Kansas City Star.

Mahomes is a rare talent, but Kingsbury helped showcase that potential and turned him into the 10th overall pick of the 2017 draft.