The San Francisco 49ers run defense was abysmal in 2016, setting records for ineptitude. There were plenty of weak spots, but one reason was the loss of linebacker NaVorro Bowman. The defense was struggling even with Bowman, but losing him in Week 4 was a big issue the final 12 games.

Pro Football Focus posted a rundown of the top run-stopping inside linebackers dating back to 2016. NaVorro Bowman ranked No. 1 among all ILBs in run stop percentage. Here is a GIF with the top five ILBs.

The top run-stopping LBs since 2006 pic.twitter.com/v5sHjtmn8E — Pro Football Focus (@PFF) May 19, 2017

They used their run stop percentage statistic, which is calculated by taking the total number of stops and dividing it by the number of run snaps played. A stop is any play that constitutes a “failure” for the offense. They offered these examples for failures and successes:

A 2-yard run on first down would be considered an offensive failure because it doesn’t really improve their position. A 1-yard run on 4th-and-inches that results in a first down, on the other hand, wouldn’t be considered a failure because the offense greatly improved their position.

NaVorro Bowman is coming off his second lower leg injury in three years. We’ve heard nothing but positives out of the offseason workout program, but we’ll still be keeping an eye on him in training camp and the preseason. The 49ers have added linebacker depth, but how Bowman bounces back will still be huge. His combination of talent and leadership are crucial for a defense that is in the midst of some significant changes.