(Zach Bland/Auburn Tigers)

A lot of Auburn’s improvement since the firing of Bryan Harsin and the promotion of Cadillac Williams to the interim head coach role can be easily explained.

The Tigers taking their running game to the next level and posting 250-plus rushing yards in three straight weeks for the first time since 2016? Williams is a running backs coach who has said he wanted to bring old-school Auburn football back. His primary play-caller is Will Friend, an offensive line coach.

What about Auburn’s pass rush having its best stretch of the season? Like the running backs, the talent was always up front for Auburn on defense this season. More rotation has helped out that group, too, with fresher legs playing deeper into games.

Auburn suddenly becoming a solid tackling unit after weeks of problems there? Again, the rotation on defense helps, along with an overall energy and effort boost that has come from the coaching change.

But the Tigers’ improvement in pass coverage? Now, that one is harder to explain.

On Saturday, Western Kentucky’s fast-paced Air Raid attack completed just 47.5% of its 59 passes for an average of 5.1 yards per attempt. Those were both season-low marks for the Hilltoppers, who have had one of the FBS’ most efficient passing games for each of the last two seasons.

Western Kentucky starting quarterback Austin Reed has his moments, especially in a second-quarter surge that saw him throw two touchdown passes to Joshua Simon. But he also threw two interceptions in a scoreless second half — including one that was returned for a touchdown by D.J. James — that gave WKU multiple picks in a game for the first time since last season’s Conference USA title game.

Since Williams took over for Harsin, Auburn has faced 157 pass attempts in three games. Opponents have combined for just 84 completions (53.5%), with the last two both finishing below the 50% mark. More importantly, Auburn is allowing just 4.96 yards per pass attempt, which is an elite number.

Let’s go back to the first eight games of the season. Mercer and San Jose State both completed too many deep passes for Auburn’s liking. Then Penn State averaged 10.1 yards per attempt in a blowout win in Jordan-Hare Stadium. Missouri and LSU struggled, then Georgia completed nearly 70% of its passes against Auburn. Ole Miss barely threw the ball at all, then Arkansas averaged 9.8 yards per attempt.

But all three of Auburn’s opponents since the coaching change have finished with fewer than six yards per pass attempt. The last time the Tigers had such a three-game stretch was in 2019, when a truly spectacular Auburn defense dominated Ole Miss, Georgia and Samford’s passing attacks.

“From D-Hall to Colby Wooden to Owen Pappoe, to that secondary, to the d-line, to the linebackers — oh my, I love watching those guys play defense,” Williams said. “I tell them all the time, my heart is on the defensive side. I love to watch them play defense. Like I told them, man, let's simplify. Let's make our adjustments.

“But where we're weak in numbers or players, let's make up for it with our effort, us playing together as a team, us winning our individual battles. Now, we can play Auburn ball as a team, because as much as this is a team sport, there are still a lot of 1-on-1 battles there that you've got to execute — and you've got to whoop the guy in front of you.”