When you lose five games by a touchdown or less, it's usually a combination of things.

But for the University of South Dakota defense in 2016, it was one glaring deficiency that kept coming back again and again.

The Coyotes inability to stop opponents from eating up huge chunks of yardage on the ground was one of the key factors in USD's eventual 4-7 record - a mark that easily could have been flipped.

South Dakota's defense allowed, on average, more than 250 yards a game on the ground last season. In all, opponents rushed for more than 200 yards seven times. Five of those ended in Coyote losses. Two opposing teams (New Mexico, South Dakota State) topped 400 yards. Ten different players topped 100 yards rushing in a game.

Needless to say, stopping the run is priority number one in Vermillion this season.

Up front, Seniors Jake Leohr and Taylor Lambert return as starters. Lambert led the Coyotes with nine-and-a-half tackles for loss in 2016.

Apart from those two veterans, they youth movement is on with sophomores Darrin Greenfield and Kameron Cline expected to fill the other two spots.

With an increased emphasis on a bigger and stronger defensive line, seven true freshmen have been brought in - six are 6-3 or taller and weigh in excess of 250 pounds.

The Coytes have depth and leadership at linebacker, and get a big boost with the return of senior John Wessel. The Sioux Falls native only played in part of one game in 2016, and sat out the rest of the year with an injury. He started 25 games the previous three seasons and was USD's third leading tackler in 2015.

Three other starters return at linebacker - senior Jim Litrenta and juniors Alex Gray and Alex Coker. Litrenta was the second leading tackler last season. Gray had two interceptions. Coker added three sacks.

USD is strong in the secondary as well, with a trio of starters back. Junior cornerback Danny Rambo had three picks last season. Senior cornerback Adam Harris was the third leading tackler. Junior safety Andrew Gray had ten tackles in one game in 2016.

At the other safety, a number of players could see action, including senior Doug Lewis, who started two games last season, and sophomore Mike Johnson, a transfer from Iowa State.

Overall, despite their struggles to stop the run, the South Dakota defense was quite opportunistic last season, picking off 12 passes and recovering 11 fumbles for a plus-five turnover margin.

USD opens the season, Saturday, September 2, at Drake.

I talked with linebacker John Wessel about his return this year and what he expects from the Coyote defense in 2017: