The Bears’ signing of Vikings DE Jared Allen marked the 30th free agent signing in the NFC North this off-season, all of them coming from within the division.

“Unfortunately league rule prohibit us from signing free agents outside the NFC North,” said Bears GM Phil Emery. “I’ve not actually seen this rule, but since teams in our division are only signing free agents from other teams in this division it has to be the case.”

So far this off-season, Emery has signed players from each of the Norris Division’s other teams. The Packers and Vikings countered by signing Julius Pepper and Corey Wootton away from the Bears, respectively. Another team’s executive said there’s a sound strategy behind the division’s incestuous behavior.

“Yes, I’m sure there are plenty of talented players coming out of other divisions,” said Lions GM Martin Mayhew. “But we’d like to keep our talent in the NFC North family until we can do better than win one playoff game in the last three seasons. Once that happens we might be better-suited to open things up for the rest of the league.”