Mel Kiper's Big Board for 2019 NFL draft: Top 25 prospects and position rankings

The NFL combine ahead of the 2019 draft is only three weeks away. That's when we'll finally get accurate measurements on every prospect in this class, and that's when NFL teams will start to cement their draft boards.

With the Senior Bowl over and done with, my updated Big Board rankings for the 2019 class are below. I'm including my latest look at the top 10 prospects at every position, from quarterbacks all the way to kickers and punters. You'll notice some big changes down the list, as I got the complete tape on the 2018 season for every player.

We now know the order for the first round of the draft, and my Mock Draft 2.0 will be out in two short weeks. In the meantime, check out my first mock draft, which came out on Jan. 17. On to the Big Board:

Note: One asterisk denotes that the player is a junior, and two asterisks denote that the player is a redshirt sophomore in 2018.

Jump to the position rankings

1. Nick Bosa, DE, Ohio State*

Height: 6-foot-4 | Weight: 263 pounds | Previously: 1

Bosa remains No. 1 here, and I had him to the Cardinals at the top of my Mock Draft 1.0. He's expected to make a full recovery from the core muscle injury that ended his Ohio State career early, and he could do some workouts at the combine soon. Bosa is an elite pass-rusher who is advanced for his age in his technique; you can probably thank his brother, Joey Bosa, and dad, John, both former first-round picks. He finished his college career with 17.5 sacks in two-plus seasons, most of which were in a loaded line rotation.

2. Quinnen Williams, DT, Alabama**

Height: 6-4 | Weight: 289 | Previously: 2

Williams was one of college football's best players -- not just defenders -- this season. And it showed, as he finished eighth in the Heisman Trophy voting. He dominated LSU with 2.5 sacks and 10 total tackles, and he finished the season with 8.0 sacks and 19.5 total tackles for loss. When I wrote about Williams after the LSU game, I mentioned his ability to use his hands to disengage from blockers. He is so good at destroying double-teams. Williams played only one full season for the Tide, but he was tremendous. He's the best 3-technique penetrator in this draft.

3. Josh Allen, OLB, Kentucky

Height: 6-5 | Weight: 230 | Previously: 3

I pegged Allen before the season as a potential Day 2 pick, after he broke out in 2017 with seven sacks, 66 tackles and one interception. But then he went and had 17 sacks -- with five forced fumbles -- and was dominant this season. I had him all the way up to No. 2 to the 49ers in my first mock draft. Allen is disruptive, and he has the length that NFL teams love as a 3-4 outside linebacker.