Mel Kiper Jr.'s Big Board: Ranking top 2018 prospects

Stock watch: QB studs and duds (1:19)

This was labeled the "Year of the Quarterback," thanks to a bevy of talent that includes Sam Darnold, Lamar Jackson, Baker Mayfield, Josh Rosen and more. With half of the season in the books, how have the top signal-callers fared? (1:19)

In this edition of my Big Board for the 2018 NFL draft: two new entrants from my last update, plus a shuffling in the top five. There's also a new No. 1 pass-rusher.

A reminder:

  • The write-ups here won't change much week to week.

  • Keep in mind that several prospects listed here have started only one season, so my projections are based on size, athletic ability, statistics and what I hear from people around the league.

  • Speaking of size, what's listed here is provided by the schools. These numbers could vary greatly when players show up at the NFL combine. True height and weight really matter for almost every position.

Note: One asterisk denotes player is a junior, and two asterisks denote player is a redshirt sophomore for the 2017 season.

1. **Sam Darnold, QB, Southern California

Previous rank: 1

Todd McShay and I went in depth on the quarterback class earlier this week. It has a chance to be special. Darnold is still my top guy -- he has everything NFL teams want in a starter. He has a big frame (6-foot-4, 225 pounds), makes quick decisions and is an accurate, natural passer. He completed 67.2 percent of his passes last season and ranked second in the nation in Total QBR (86.8). Darnold has thrown too many interceptions to start the 2017 season -- nine in six games -- and needs to be more consistent. His Total QBR has dropped because of the turnovers (68.5). The third-year sophomore is an exciting prospect who could go No. 1 overall in April's draft.