This article is part of our Conference Preview series.

Spring practices are getting started all across the country, which means Rotowire will be kicking off a series of previews for some of the nation's top positional battles. For this article, we'll be looking at the quarterback picture for each Big 12 team heading into spring. Last year's conference champion and College Football Playoff representative Oklahoma will have big shoes to fill with the departure of 2017 Heisman winner Baker Mayfield moving on, but so do many of the top contenders from a season ago.

BAYLOR

The Incumbent:Charlie Brewer (So.)

The Challenger(s):Gerry Bohanon (Fr. - Early Enrollee), Jalan McClendon (Sr.)

The Skinny: Brewer finally received his shot under center in October last season, taking over the starting gig from Zach Smith after he and Anu Solomon both proved ineffective under center for the Bears. Brewer's first significant taste of game action came against West Virginia when he almost led the Bears to a comeback victory by passing for two touchdowns in a two-point loss. He didn't start the next week, but entered once again the next week against Texas and retained the starting job the rest of the way, posting an 11:4 TD:INT ratio and a 68.1 completion percentage. Smith transferred to Tulsa in the offseason, leaving Brewer as the only returning quarterback. While the Bears added early enrollee Gerry Bohanon and transfer Jalan McClendon to the mix, Brewer should start Week 1.

IOWA STATE

The Incumbent:Kyle Kempt (Sr.)

The Challenger(s):Zeb Noland (So.)

The Skinny: Kempt began the 2017 season as the backup to Jacob Park, but some personal issues led to Park's departure from the team and the reins landing in Kempt's lap. The senior took advantage of the opportunity, proceeding to post a 15:3 TD:INT ratio and a 66.3 completion percentage over nine games under center. His most impressive feat came in his first start when he led the Cyclones to one of the biggest upsets in recent memory with a win over Oklahoma in Norman. He was granted a sixth year of eligibility during the offseason and enters the 2018 campaign essentially locked into the starting role for the Cyclones. Park transferred, leaving Zeb Noland -- who filled in a couple times when Kempt was injured -- as the backup and freshman Re-al Mitchell -- a mobile option under center -- as the favorite for the third-string job with the possibility of being inserted in some speed packages.

KANSAS

The Incumbent:Carter Stanley (Jr.)

The Challenger(s):Peyton Bender (Jr.), Miles Kendrick (So.)

The Skinny: Bender actually won the starting job out of fall camp in 2017, but a rough stretch under center once conference play started eventually led to his benching. Stanley took things over against Kansas State and guided the offense in the next four games before a knee injury opened one last start for Bender against Oklahoma State in the finale. Neither of the two signal-callers staked a claim to the starting job in 2018 with their performances, with each completing less than 55 percent of his passes. Miles Kendrick -- who transferred from a junior college and enrolled early -- joins the fray this spring and the trio figure to have it out on the gridiron into the fall before second-year coach David Beaty makes a decision on a starter.

KANSAS STATE

The Incumbent: It's complicated

The Challenger(s):Alex Delton (Jr.), Skylar Thompson (So.)

The Skinny: In likely the most even battle among Big 12 contending starters in 2018, Delton and Thompson appear to be in a dead heat for the K-State starting job, per Kellis Robinett of The Wichita Eagle. While two quarterbacks enter, coach Bill Snyder's historical approach at the position suggests only one will leave receiving consistent reps under center. Both signal-callers share a dual-threat quality and each led the team to an important victory -- Thompson against Oklahoma State and Iowa State and Delton in the Cactus Bowl over UCLA. Given Thompson's victories over two impressive opponents last season, he gets the estimated starter tag, but it's just a guess at this stage.

OKLAHOMA

The Incumbent: Gone with Heisman Trophy-winner Baker Mayfield off to the NFL

The Challenger(s):Kyler Murray (Jr.), Austin Kendall (So.)

The Skinny: It will be tough for the Sooners to replace reigning Heisman Trophy winner Baker Mayfield under center, but one of Murray or Kendall will be tasked with doing just that. Kendall served as Mayfield's backup during the 2016 season before redshirting last season to keep another year of eligibility. Murray, on the other hand, arrived on campus in Norman in 2016 via transfer from Texas A&M but had to sit out a season before being eligible to play. He backed up Mayfield last season while Kendall employed his own redshirt. The 30th ranked player in the 2015 class and second-ranked dual-threat quarterback, according to 247Sports Composite, Murray fits the system better than Kendall -- a pro-style quarterback. Murray has also received the most fanfare and seems to have an unspoken edge in the competition entering spring after completing 85.7 percent of his limited passes (21) for 359 yards and three touchdowns last season. Unless Murray struggles mightily in spring and fall and Kendall shines, it's likely Murray's job to lose.

OKLAHOMA STATE

The Incumbent: N/A with Mason Rudolph also heading to the NFL.

The Challenger(s):Dru Brown (transfer from Hawaii), Taylor Cornelious (Sr.), Keondre Wudtee (So.), Spencer Sanders (Fr.)

The Skinny: Like in-state rival Oklahoma, the Pokes will have to replace an NFL-bound quarterback in Mason Rudolph. However, unlike Oklahoma, there are plenty of candidates looking to fill the void at the position. Cornelious' 24 pass attempts over the last three seasons amounts to the most experience of any of the options while wearing a Cowboys uniform. Wudtee lost the backup job to him last season and, while they've split first-team reps early in camp, he likely has a leg up in that race. With a strong spring, he may have a big head start for the starting job by the time both Brown and Sanders step foot on campus in Stillwater come June. Brown threw for 2,785 yards, 18 touchdowns and eight interceptions at Hawaii a season ago and Sanders may possess the most upside in the long run, but Cornelius garners my vote for the job, especially if he pieces together a nice spring showing.

TCU

The Incumbent: N/A following Kenny Hill's graduation

The Challenger(s):Shawn Robinson (So.), Michael Collins (Penn transfer), Justin Rogers (Fr. - Early Enrollee)

The Skinny: Hill led the Horned Frogs' offense each of the last two seasons, but his graduation leaves an opening. Robinson enters the picture as the head-and-shoulders leading candidate to seize the role, a notion backed by coach Gary Patterson, according to Stefan Stevenson of the Fort Worth Star-Telegram. Unless something drastically changes during spring or fall practice, the job should be Robinson's to lose after he started and led TCU to a road victory over Texas Tech last season. Collins and Rogers have also impressed early in camp, suggesting Robinson's leash may be short if he struggles. However, Robinson remains the favorite to start Week 1 for now.

TEXAS

The Incumbent: Two quarterbacks (see below)

The Challenger(s):Shane Buechele (Jr.), Sam Ehlinger (So.)

The Skinny: The Longhorns couldn't decide what to do under center last season between the two signal-callers, leading to a timeshare for much of the second half of the campaign. While neither Buechele nor Ehlinger played poorly, neither of the two really separated himself in the competition either. Buechele may have played slightly better under center, completing 64.3 percent of his passes and posting a 7:4 TD:INT ratio. However, Ehlinger was more willing to push the ball down the field, evidenced by his higher yards per attempt -- 6.96 versus Buechele's 6.6 -- despite a lower completion percentage and added an 11:7 ratio of his own. While coach Tom Herman rolled with the committee approach in 2017, it wouldn't be surprising if he looks for a full-time starter this season after only experiencing moderate success during his first year in Austin. Ehlinger, per the Austin-American Statesman took first-team reps ahead of Shane Buechele at practice on March 27, so perhaps he's surged slightly ahead in the tightly contested battle.

TEXAS TECH

The Incumbent: Another departure

The Challenger(s):McLane Carter (Jr.), Jett Duffey (So.), Alan Bowman (Fr. - Early Enrollee)

The Skinny: While Nic Shimonek doesn't possess the NFL hype of some of the other Big 12 quarterbacks entering the 2018 NFL draft, he did compile an impressive senior campaign for the Red Raiders in 2017. Now off the radar, Carter and Duffey are the expected leading candidates to step in and lead the offense. A recent wrinkle may throw a wrench in the chase for a starter. Duffey was arrested March 25 and has been suspended by coach Kliff Kingsbury indefinitely, according to the Dallas Morning News. Duffey's suspension likely puts Carter in the driver's seat to start for Texas Tech in Week 1, though Bowman is expected to receive additional reps as a result of the suspension and will get an opportunity to show his worth. It wouldn't be surprising to see Duffey rejoin the competition in the fall, but he may be too far behind at that point.

WEST VIRGINIA

The Incumbent: Finally, some continuity - Will Grier (Sr.)

The Challenger(s): Realistically, none

The Skinny: There isn't much to say about the quarterback spot in Morgantown. Grier held the starting role last season before a broken finger left him sidelined for most of the final three games in 2017. Prior to his injury, Grier threw 3,490 yards, 34 touchdowns, and 12 interceptions, leading the Mountaineers to a 7-3 record in his 10 full games. Chris Chugunov did his best to replace the junior under center, but the level of competition proved too high and he struggled mightily. Jack Allison -- a redshirt sophomore transfer from Miami -- has a better chance of growing a beard, buying a musket and a pelt coat and leading the team on to the field as the team mascot than prying the starting job from Grier. However, he has set himself up to serve as Grier' successor and will remain on hand as the backup in 2018. Freshman Trey Lowe figures to fill out the depth chart as the third-string option unless he elects to redshirt.