Mark J. Terrill/Associated Press

Watching the opening round of the 2018 NFL draft unfold should be the best drama on television April 26. The number of different possibilities inside the top five selections is off the charts, and the outcomes will have a trickle-down effect on the remaining 27 picks of the first round and beyond.

That's mostly because of the quarterbacks. There are six signal-callers who could land in the first round, and four of them could be off the board inside the top six. After that, there may be a number of teams wanting to move up in order to grab one of the remaining options at the sport's most important position.

Let's check out an updated mock draft for Round 1 and take a closer look at the top selections before the draft process takes center stage.

1st-Round Mock Draft

1. Cleveland Browns: Sam Darnold, QB, USC

2. New York Giants: Josh Rosen, QB, UCLA

3. Indianapolis Colts: Bradley Chubb, DE, NC State

4. Cleveland Browns (from HOU): Saquon Barkley, RB, Penn State

5. Denver Broncos: Josh Allen, QB, Wyoming

6. New York Jets: Baker Mayfield, QB, Oklahoma

7. Tampa Bay Buccaneers: Arden Key, DE, LSU

8. Chicago Bears: Orlando Brown, OT, Oklahoma

9.* Oakland Raiders: Josh Jackson, CB, Iowa

10.* San Francisco 49ers: Calvin Ridley, WR, Alabama

11. Miami Dolphins: Quenton Nelson, OG, Notre Dame

12. Cincinnati Bengals: Roquan Smith, LB, Georgia

13. Washington Redskins: Derwin James, SS, FSU

14. Green Bay Packers: Denzel Ward, CB, Ohio State

15. Arizona Cardinals: Mason Rudolph, QB, Oklahoma State

16. Baltimore Ravens: Courtland Sutton, WR, SMU

17. Los Angeles Chargers: Rashaan Evans, LB, Alabama

18. Seattle Seahawks: Mike McGlinchey, OT, Notre Dame

19. Dallas Cowboys: Maurice Hurst, DT, Michigan

20. Detroit Lions: Minkah Fitzpatrick, FS, Alabama

21. Buffalo Bills: Lamar Jackson, QB, Louisville

22. Buffalo Bills (from KC): Connor Williams, OT, Texas

23. Los Angeles Rams: Malik Jefferson, LB, Texas

24. Carolina Panthers: James Washington, WR, Oklahoma State

25. Tennessee Titans: Sam Hubbard, DE, Ohio State

26. Atlanta Falcons: Harold Landry, LB, Boston College

27. New Orleans Saints: Christian Kirk, WR, Texas A&M

28. Pittsburgh Steelers: Ronnie Harrison, SS, Alabama

29. Jacksonville Jaguars: Mark Andrews, TE, Oklahoma

30. Minnesota Vikings: Kolton Miller, OT, UCLA

31. Philadelphia Eagles: Jaire Alexander, CB, Louisville

32. New England Patriots: Derrius Guice, RB, LSU

Oakland and San Francisco will flip a coin to determine the Nos. 9 and 10 picks. Pick Nos. 29-32 will be finalized after the playoffs.

Analyzing Top Selections

1. Cleveland Browns: Sam Darnold, QB, USC

The Cleveland Browns have two potential routes with a pair of picks inside the top four. They could go conservative, taking their preferred quarterback with the No. 1 choice, and then see who's available at No. 4. Or if they fall in love with one of the other prospects, perhaps NC State defensive lineman Bradley Chubb, the front office could select him and still be guaranteed a top QB option with the fourth selection.

It seems likely Cleveland will start the draft with a quarterback, though. Team owner Jimmy Haslam strongly suggested that while introducing new general manager John Dorsey in December.

"[Finding a quarterback] will be John's No. 1 priority," Haslam told reporters. "The Cleveland Browns are not going to be successful until we get a quarterback. We're going to do whatever it takes to find [the] quarterback we need to be successful.''

The good news for the Browns is there's no shortage of options in this year's class. The bad news is there's no consensus pick among them, which puts more pressure on the front office's evaluations.

While Sam Darnold wasn't able to match his standout freshman campaign as a sophomore, he still threw for over 4,100 yards and completed 63.1 percent of his throws for USC in 2017.

His overall numbers at USC are terrific, with 57 passing touchdowns and 22 interceptions across 27 games. He added 322 yards and seven scores on the ground, showing he's more than a pocket passer.

Those numbers, paired with the arm talent to make all the NFL throws, should put him in the driver's seat to get picked by Cleveland. But that could change before draft day.

2. New York Giants: Josh Rosen, QB, UCLA

This represents an ideal fit for both team and player.

The New York Giants must start preparing for the post-Eli Manning era. Whether that arrives this fall or the organization opts to wait until 2019, when the dead-cap hit would be easier to swallow, there will soon be a changing of the guard in New York.

Meanwhile, Josh Rosen explained to Josh Weinfuss of ESPN in December he would prefer to land with the "right team," presumably meaning one with some proven pieces instead of one in a total rebuild.

"I'd rather be a lower pick at the right team than a higher [pick] at the wrong team," he said.

While the Giants are coming off a forgettable 3-13 campaign, they were 11-5 and earned a playoff berth in 2016. Some narrow losses during an 0-5 start and numerous key injuries, headlined by the loss of star wideout Odell Beckham Jr., made the team look worse than it should be moving forward.

Rosen, who posted career highs in passing yards, touchdowns and completion rate during his final year with the UCLA Bruins, could help lead a quick turnaround in New York. At worst, he would sit and learn from Manning for a season and take the reins of the offense next year.

3. Indianapolis Colts: Bradley Chubb, DE, NC State

Although the Indianapolis Colts' immediate future rests heavily on quarterback Andrew Luck and the weapons around him as he works back from a shoulder injury, the team must focus on long-term fixes defensively at some point. It's been an issue since the days when Peyton Manning was carrying the franchise on his back.

There were few reasons of optimism on that side of the ball in 2017. Indianapolis ranked 30th in points allowed, 28th in passing yards allowed and 26th in rushing yards allowed. And without Luck, it didn't have the offensive firepower to keep pace, leading to a 4-12 record.

PFF Draft showcased how Chubb could help turn things around:

Along with those bottom-tier baseline numbers, the Colts also finished 31st in sacks. Getting more pressure on the opposing QB is the first step toward getting the defense to at least a league-average level.

Chubb registered 25 sacks in 38 games across his final three years with the Wolfpack. That includes back-to-back 10-sack seasons in 2016 and 2017.

Getting a healthy Luck back to lead the offense and drafting Chubb to lead the pass rush would give Indy a great chance of returning to playoff contention next season regardless of its other upgrades.