In an offseason full of coach and player movement for the Chargers' three AFC West rivals, one thing is certain:
The advantage under center lies in Los Angeles.
Philip Rivers has started 192 regular season games -- that's 91 more than the other three starting quarterbacks in the AFC West combined.
Let's spin around the division with an emphasis on the signal callers, two of which are fresh faces:
Kansas City Chiefs: The back-to-back division champs have officially given the keys to second-year quarterback Patrick Mahomes. The cleats he's tasked to fill are big, too.
Mahomes' predecessor Alex Smith -- who was officially traded to the Washington Redskins in March -- compiled a 50-26 regular season record in five seasons as the starter in Kansas City. The three-time Pro Bowler was also 7-1 against the Chargers during his time with the Chiefs.
Mahomes' lone NFL start came last season in a Week 17 win in Denver against the Broncos. The then-rookie went 22 of 35 for 284 yards and an interception.
Kansas City traded up to select Mahomes 10th overall in the 2017 NFL Draft. The Texas Tech standout was backed up by current Chargers quarterback Nic Shimonek in college.
Mahomes, 22, was just eight years old when Rivers, 36, entered the league in 2004. On Sept. 9, they'll square off in the season opener at StubHub Center.
Oakland Raiders: Perhaps the NFL's biggest offseason storyline was the return of Jon Gruden to the NFL sidelines. And while expectations are high across the board for Gruden in Oakland, no task is more important than elevating the play of his 27-year-old quarterback, Derek Carr.
Carr -- plagued by injury, drops and spotty offensive line play -- went 6-9 last season as the starter after signing a five-year contract. He's also had a carousel of coaches during his brief NFL career.
Since entering the league in 2014, Carr has worked with four head coaches and three offensive coordinators. Gruden's 10-year deal, coupled with the return of Carr's first NFL OC Greg Olson, signals that offensive stability is there to stay.
Carr threw for 3,496 yards last season, including 22 touchdowns and 13 interceptions. He's 9-14 all-time against the AFC West and 4-4 against the Chargers, losing both games to Los Angeles in 2017.
Denver Broncos: The league's 27th-ranked scoring offense received some much-needed help this offseason after signing free-agent quarterback Case Keenum to a two-year deal.
A career journeyman, Keenum, 30, found his groove last season in Minnesota. The six-year veteran was thrust into action after a Week 1 injury to Sam Bradford and never looked back. He posted an 11-3 record in the regular season and threw for a career-high 3,547 yards and 22 touchdowns, with just seven interceptions. The Vikings fell to the eventual Super Bowl-champion Philadelphia Eagles 38-7 in the NFC Championship Game.
The Broncos will be Keenum's fourth NFL team, but unlike in Minnesota, he enters 2018 as the unquestioned, season-long starter. He also has ties to the organization.
Keenum started his career with the Houston Texans, where Broncos senior personnel advisor Gary Kubiak was the head coach. Denver's current head coach Vance Joseph was also there during most of Keenum's tenure with the Texans, serving as defensive backs coach.
Keenum has a career regular season record of 20-18. He's never faced the Chargers.
