The Curious Case of the Combine Arm Length

    

    Something strange is happening with prospect measurements this year, particularly when it comes to arm length for offensive linemen. Offensive tackles face the most scrutiny when it comes to physical measurements because of their crucial role in protecting quarterbacks. NFL teams generally prefer their tackles to have an arm length of at least 34 inches, with 33 inch arms being good enough to get by. It is almost unheard of for a long-term NFL starter at tackle to have arms shorter than 33 inches long. However, multiple offensive linemen who have been measured twice during the pre-draft process have seen significant discrepancies between their numbers, larger than what has been observed in previous years.

    At this year’s NFL Combine, scouts were eager to get official measurements on some of the top offensive line prospects, but the results raised more questions than answers. Many of the most desired tackles came in with shorter-than-expected arms, with the majority of prospects falling below the desired 34 inches. While a few fractions of an inch might not seem like a big deal in the grand scheme of things, these measurements carry weight in NFL draft evaluations. Arm length has historically been one of the most reliable markers in determining whether a lineman has the necessary physical stature to stay at tackle, or if they may need to move inside and learn how to play as a guard.

    There might not be any prospect in this class with more riding on his arm length measurement accuracy than LSU's Will Campbell. The projected top tackle in the class, Campbell measured at 32 5/8 inches at the Combine, which ignited widespread speculation in the media about whether or not he could really be a tackle in the NFL. Then, surprisingly, Will Campbell got measured again by a league official at LSU’s Pro Day. This time his arms were exactly 33 inches long. 

    Other notable prospects who saw their arm length measurements fluctuate over the last couple of months include Marcus Mbow from Purdue, Aireontae Ersery from Minnesota, Josh Connerly from Oregon and Armand Membou from Mizzouri. All four of them are currently expected to get drafted in the first round or two, and all four of them saw a decrease of at least half an inch in their arm length measurements between the Senior Bowl and the Combine. The differences between Combine measurements and the measurements taken at other events is seen across other positions as well, but the arm length measurements of offensive lineman has gotten the most attention due to that generally agreed upon 33 inch minimum. 

    A team interested in drafting a tackle isn't going to want to pick player that they think will need to move inside to guard unless they also have a need at guard, and the positional values of guards as it relates to draft capital is a lot lower than that of tackles which might cause teams to consider drafting another position before attempting to address that need. Multiple teams picking inside the top 10 of this draft would be leaping at the opportunity to draft Will Campbell if his arms were consistently measuring 33 inches or longer, but these measurements fluctuating as much as they are has thrown a lot of uncertainty into the mix. All of this forces us to confront a few key questions: Did something happen with the Combine measurements causing their numbers to be lower than they should have been, or are the other measurements at events like the Senior Bowl, the Shrine Bowl, or team Pro Days higher than they should be? And how important will those numbers be to teams on Draft Night?