Sometimes the best ability is availability. This couldn't have seemed more true in a year in which NFL teams' seasons were spoiled by injuries to star players.
With that sentiment in mind, we compiled the NFL's 2017 Iron Man team. In order to qualify, players had to meet two criteria:
They had to have finished at or near the top of their position in terms of snap count; and
Graded well when they were on the field, according to our data at Pro Football Focus.
There are some no-brainers -- players who have been iron men throughout their careers -- along with a few surprises and a couple of rookies. Of course, there was room for only so many players, so we included a number of honorable mentions too.
OFFENSE
Quarterback: Tom Brady, New England Patriots
Regular-season snaps: 1,115 | PFF grade: 95.0
No other signal-caller saw as many snaps as the ageless wonder Brady. At 40 years old, he continues to roll back the clock with a consistent level of excellence. His 96.6 passer rating when under pressure not only ranked first in the NFL by a significant margin -- Tampa Bay's Jameis Winston was second at 83.9 -- but would be good enough to rank eighth among all quarterbacks in total overall passer rating.
2018 outlook: It seems foolish to try to predict when the decline will finally come for Brady. Quarterbacks aren't supposed to be this good this late in their careers, but Brady continues to dominate.
Honorable mention: Blake Bortles, Jacksonville Jaguars (1,103 regular-season snaps)
Running back: Le'Veon Bell, Pittsburgh Steelers
Regular-season snaps: 943 | PFF grade: 85.3
Playing under the franchise tag, the Steelers got their money's worth with Bell in 2017. His 943 snaps on offense were 145 more than the next-highest running back. He also led all backs in rushing attempts (321), finishing with 34 more than Buffalo's LeSean McCoy. Bell didn't grade out as the top running back in the NFL, but he was effective and didn't slow down with his significant workload, averaging 2.6 yards after contact per carry and forcing 61 missed tackles on 406 total touches.
2018 outlook: Bell is still young, about to head into his age 26 season, but it will be interesting to see how his body holds up with such a vigorous workload. The decision on whether to franchise him again looms large for the Steelers, and a long-term deal with that workload carries its risks.
Honorable mention: Todd Gurley, Los Angeles Rams (788 regular-season snaps)