Tiers are a practical way of displaying rankings for optimal use on Draft Day. The goal is to accentuate which position is closest to a drop-off by denoting where the drop-offs are at each position. During the heat of the draft, you'll know that the position to target is the one that's current tier is closest to depletion.
Below are the relief pitcher tiers for 2021, which only depict those projected to close, apart from The Next in Line tier.
The Elite: Josh Hader, Liam Hendriks
The Near-Elite: Raisel Iglesias, Emmanuel Clase
The Next-Best Things: Kenley Jansen, Ryan Pressly, Edwin Diaz, Jordan Romano, Aroldis Chapman, Craig Kimbrel
The Fallback Options: Giovanny Gallegos, Camilo Doval, Will Smith, Scott Barlow, Mark Melancon
The Last Resorts: Corey Knebel, Dylan Floro, Joe Barlow
The Deep-Leaguers: Drew Steckenrider, Lucas Sims, Taylor Rogers, Lou Trivino, Gregory Soto, Andrew Kittredge, Garrett Whitlock, David Bednar, Carlos Estevez, Rowan Wick, Cole Sulser, J.B. Wendelken
The Next in Line: Paul Sewald, Devin Williams, Blake Treinen, Michael Fulmer, Kendall Graveman, Chris Stratton, Jake McGee, Anthony Bender, Matt Barnes, Ken Giles, Mike Mayers, Collin McHugh, Tyler Matzek, Chad Green, Jose Alvarado, Tyler Wells, Tanner Rainey, Spencer Patton, James Karinchak, Diego Castillo, Josh Staumont, Art Warren, Kirby Yates