Through the first eight weeks of the NFL season, teams are averaging a combined 40.4 points per game. That is more than a full point less than at the same point a year ago and on pace for the lowest scoring campaign since 1993.

	Blake Brockermeyer, right, and the Bears' offensive line have been a fixture for Chicago.

While most observers attribute the scoring malaise to improved defensive play, the ability of front seven units to stifle the run and of secondaries to curtail upfield vertical passing attacks, a factor that should not be overlooked is the lack of continuity in most offensive line quintets around the league.

Over the first half of the season, several teams have been forced to reshuffle blockers on a near-weekly basis. The result is a lack of basic cohesiveness that clearly impacts every aspect of offensive play.

"There hasn't even been a single week yet in which we've had the starting five that we liked in camp together in a game," Bills general manager Tom Donahoe said. "Not only hasn't our top five started together, they haven't even played a snap together. That makes it pretty hard to function."

Indeed, the Bills have started five different players so far at the two offensive tackle spots and are one of four franchises that has been forced, primarily because of injuries, to use four different starting combinations on the line. Sixteen teams have used at least three different starting units.

Entering this weekend, there have been 76 different starting offensive line units around the league, an average of 2.45 per team.

Only six teams -- Arizona, Chicago, Cincinnati, Dallas, Green Bay and San Diego -- have started the same offensive lines in every game. Not surprisingly, four of those teams own winning records, and the aggregate mark for the six franchises is 24-19.

By comparison, the teams that have started four different units are a combined 13-18 and, of the group, only Baltimore (5-3) has a winning record. The Super Bowl champs, however, have featured a whirling-dervish offensive line most of the season.

	“	You look around and see teams plugging in two or three new guys every year, and that's hard. It's really tough when injuries hit in season and you're switching bodies all over the place. You really can't get a feel for each other under those circumstances. ”
		— James "Big Cat" Williams, Bears offensive tackle

That the Packers and Bears will square off Sunday in a key NFC Central game at Soldier Field with their line units intact is a rarity. But officials from both teams acknowledge the play of their line units (together since training camp) has been essential to their success. In part, it is a carryover from the 2000 campaign, since the Bears and Packers have had to replace just one starter each on O-line from last year.

"When it comes to the offensive line, familiarity just breeds success," said Bears right tackle James "Big Cat" Williams, who has lined up next to guard Chris Villarrial for five straight seasons in the starting lineup. "They've done a good job here keeping this group together. You look around and see teams plugging in two or three new guys every year, and that's hard. It's really tough when injuries hit in season and you're switching bodies all over the place. You really can't get a feel for each other under those circumstances."

Bills guard Corey Hulsey, starting in place of the injured Jerry Ostroski, has had three different right tackles next to him this year. He says there have been times when he isn't sure who is aligned at the position.

The great leaguewide line shuffle certainly has been at least part of the explanation for the blunted scoring this year. After 113 games in 2000, teams were averaging 41.6 points per game, compared to the 40.4 points in the same number of 2001 contests. If the trend were to continue over the entire season, it would be the lowest scoring year since 1993, when games averaged just 37.4 points.

Len Pasquarelli is a senior NFL writer for ESPN.com.