During the 2020 offseason the Las Vegas Raiders signed free agent quarterback Marcus Mariota. Mariota was selected 2nd overall in 2015 by the Tennessee Titans, but after his second year he started on a downward spiral. In his 5 years with the Titans, Mariota recorded 1110 completions in 1765 attempts, with 13,207 passing yards, 76 touchdowns, and 34 interceptions, along with 1399 yards rushing and 11 touchdowns. Compared to Carrs' stats over the past 5 years, they stand at 1772 completions in 2714 attempts, along with 19,523 passing yards, 122 touchdowns, and 50 interceptions. Carr also had 403 yards rushing and 3 touchdowns.
There are simple explanations for the stats you see above. Mariota is more of a mobile QB than Carr, so he can use his legs and scramble for big yardage while Carr, who doesn't have much speed, he doesn't use his legs often. Carr throws more so he is subjected to more interception chances, but he has a 1.74% interception percentage, while Mariota has a 2.5% interception percentage. That shows Marcus throws more interceptions than Carr because even though Carr throws more than Mariota, Carr throws less picks in the long run, Mariota gets picked more often when he throws than Carr.
I believe along with other people that Mariota can jump Carr during the season just like Tannehill did to him last year. The Raiders have not had a mobile QB since Terrelle Pryor from 2011-2013 and it has flawed their offense. If they add Mariota as their starter then defenses have to always keep a QB run in mind and that will take a little bit of attention off RB Josh Jacobs and WRs Henry Ruggs III, Hunter Renfrow, Tyrell Williams, and TE Darren Waller. Mariota throws a nice ball, probably better than Carr. Mariota can improvise and has the mobility to extend plays, for Carr it's harder for him to move around in the pocket and doesn't have the improvising experience in the NFL. Marcus has won playoff games and has been three more than Derek, which just alone makes him extremely valuable for a young and inexperienced Raiders offense.
He fits the offensive scheme perfectly, in Tennessee they went through a few head coaches and coordinators along with no talented, primary target for most of the time he was there. Las Vegas definitely has a more-- stable offense than Tennessee did, something Mariota will definitely be apart of one way or another. One thing Mariota will have left behind is a better defense, if Mariota does become the starter then the defense will need to be able to stall offensive drives. Head Coach Jon Gruden has given high praise to Marcus Mariota by calling him a 'dazzling playmaker' per ESPN.com. Gruden has gained multiple playmakers in just one offseason. Last year teams clued in on then rookie RB Josh Jacobs which made it hard for them to utilize him, this year they draft a speed demon in Henry Ruggs to take the top off the defense so it will be easier to use Jacobs. If you throw Mariota in that mix then you have two players in the backfield who can run as if you play Carr than only Jacobs will have the running and speed attributes.
Defenses' would need to adjust how they play the Raiders if Mariota starts over Carr mid-season. Defensive coordinators will need to address a possible QB spy on Mariota or play an extra DB in in the middle of the field or a single high safety and an extra LB in the box. There is a chance Mariota could be the starter by week 9, that's when they play the Chargers. For example, the Chargers drafted Kenneth Murray 20th overall, if the Chargers were to go with the single high safety which would be Derwin James, Kenneth Murray would be the extra linebacker due to his speed, plus he's a rookie so he won't have much of an impact until recently. If they were to put a DB in the middle of the field and take away a Lineman or LB, the DB would be the speedy and hard hitting Derwin James.
Too sum it all up, the Raiders would be better if Mariota can make the jump and become the starter in Las Vegas, obviously Mariota isn't a long term solution but a step in the right direction towards a playoff birth. The Raiders need to buff that secondary up and maybe get a linebacker or a quarterback in the first round next year. The ceiling for Las Vegas is 8-8 and the floor is 6-10, it's really a boom or bust season for this team.