There is a persistent domino effect rippling through the Terrapin football team in its games this season. Each week, the areas of concern change. The style of the game changes. The final result, in some way, is different.

Yet each week, Terp coach Ralph Friedgen is questioned about the offensive line. It’s been the obvious weak spot for the 2009 Terps since Dec. 31, 2008, the day after the Terps’ 42-35 win against Nevada in the Humanitarian Bowl. Five of the team’s top seven linemen graduated and moved on, several to professional careers. As a result, the Terps were left with a core group short on both experience and depth.

The tribulations of the line have been diligently reported. Quarterback Chris Turner has been sacked 22 times this season, more than any other quarterback in FBS (formerly Division 1-A). The running game has averaged just 2.7 yards per carry, as opposed to 4.3 last season. And the unit has yet to settle into any real roles, with eight players making starts and center Phil Costa, a converted guard, the only lineman to start in the same position for all six games this year.

But those numbers uncover only the top layer of the Terps’ issues. As a result of protection issues, Turner has been forced to get rid of the ball more quickly. To compensate, the Terps have kept tight ends and running backs, often viable receiving options, in to assist the line with pass blocking, giving Turner fewer options.

Offensive coordinator James Franklin often references the importance of every piece of the offense working together as a unit. The line’s struggles, then, have presented a number of challenges to the offense, particularly with the need for extra blockers.

“We’re doing some of those things to give us a chance,” Franklin said. “You don’t want to do that all the time, but we’re doing that in certain situations more than we normally have. … It gives you less options.”

In addition, this season, those options have changed. Since All-American tight end Vernon Davis first started for the Terps in 2004, Friedgen has earned a reputation for his use of tight ends. In the five years prior to this season, tight ends were responsible for 24 percent of Terp receptions.

This season, that number has dropped to just 14 percent. Certainly, those numbers reflect the losses of three high-caliber tight ends — Joey Haynos and Jason Goode in 2007, and Dan Gronkowski last season. But the statistics also measure the increased amount of pass protection demanded of the tight ends, as well as running backs and fullbacks, this season.

The effects are clear. Turner has been forced to scramble this season far more than in the past: If wide receivers struggle to get open, Turner has no choice but to tuck the ball and run or take a sack.

“When they stay in to protect, we’ve got to do our job,” wide receiver Torrey Smith said. “So it puts a lot of pressure on us.”

Smith said the Terps have also run more wide receiver screens than in the past. The insurance is necessary. On at least four of Turner’s six interceptions, the Terp quarterback was being hit while releasing the ball or hurried to the point where he could not set his feet.

Friedgen said poor pass protection is “ravaging” his offense. And while he was not soft on his tight ends, a young group aside from senior starter Tommy Galt who has 11 catches on the season, the ninth-year head coach and renowned former offensive coordinator said he has worked hard with assistant coaches to figure out how to fix the major issue in the trenches.

The matter is only made more difficult without star left tackle Bruce Campbell, the line’s most dominant force, who may miss Saturday’s game against Virginia with an MCL injury, which would be his fourth absence of the year. That leaves Friedgen, Franklin and veteran offensive line coach Tom Brattan with more continuity issues, and less experience and overall talent. If the line continues to struggle, there will also be more questions.

“My job all year is to try to make the offense successful with the personnel that we have,” Franklin said. “You can have the greatest plays in the world, but if they don’t play on your strengths and hide your weaknesses, it doesn’t matter.”

ajoseph@umdbk.com