You may have noticed that Washington Redskins rookie linebacker Ryan Kerrigan has only two sacks to his name despite appearing to have a hand in as many as 1.5 more during the first four weeks of the season.

Kerrigan, Washington’s first-round pick out of Purdue, recorded his first sack against Arizona in Week 2 of the season, then originally was credited with a half-sack in his team’s game against the Dallas Cowboys the following week. Kerrigan then recorded another sack in Week 4 at St. Louis

But, if you check his stats on, his profile reads 2.0 sacks.

What gives?

When the Cowboys game was reviewed, the official stat-keepers took Kerrigan’s half-sack and awarded it to defensive end Adam Carriker.

On the third-quarter play in which Kerrigan appeared to have a hand in the sack, the rookie rushed quarterback Tony Romo and got a hit on him, forcing a fumble (which usually counts as a half-sack). Romo recovered the fumble on the bounce, and then Carriker brought Romo to the ground.

Officially, although Kerrigan made initial contact to force the fumble, Romo was able to recover it and then had the chance to either run or throw before Carriker brought him down. So Carriker was credited with the sack, and Kerrigan the forced fumble.

Had Kerrigan been able to combine with Carriker to bring Romo down, he would’ve gotten a half-sack. Or, had Carriker – and not Romo – recovered the fumble, Kerrigan would’ve gotten the half-sack.

“We got a whole, long explanation from the Elias [Sports Bureau] on that play,” Redskins linebacker coach Lou Spanos said.

Later in that game, Kerrigan recorded another tackle on Romo behind the line of scrimmage that didn’t count as a sack, either.

In the fourth quarter, with Dallas facing first down from its own 41, a bad snap sailed past Romo, and the quarterback had to scramble 11 yards upfield to scoop up the ball. As he did, Kerrigan took his legs out from under him.

“On that one, it was a fumble recovery, and it was never established as an actual pass play,” Spanos said. “On a bad snap, with the quarterback never able to establish a throw, he was just a runner on that play.”

Kerrigan on that stop recorded a tackle for a loss rather than a sack.