Tip Sheet: The Broncos' one constant

3/19/2010 - NFL Elvis Dumervil Denver Broncos + more
The Broncos signed Jarvis Green, left, and Jamal Williams to help solidify their defensive line. Icon SMI/US Presswire

Over the past 13 months, the Denver Broncos have changed their head coach and general manager, gone through two defensive coordinators and transitioned their base scheme from a 4-3 look to a 3-4.

Still, no matter the wholesale makeover, it seems that whenever it comes to defensive linemen, the more things change in The Mile High City, the more some issues remain the same.

Like the Broncos' maddening, and apparently ongoing, inability to draft and develop their own up-front players on defense.

Despite moving to No. 7 in overall defense in 2009 (from 29th the previous season), the Broncos parted ways with coordinator Mike Nolan in January -- he took on the same role with the Dolphins -- and replaced him with linebackers coach Don Martindale. The apparent progress aside, Denver is revamping its front line, likely a result of its late-season meltdown against the run and a No. 26 ranking in '09 versus the rush. The Broncos have not ranked in the top 10 against the run since 2004.

Denver has signed three veteran linemen as unrestricted free agents in the first two weeks of the free-agency period: nose tackle Jamal Williams (San Diego) and ends Justin Bannan (Baltimore) and Jarvis Green (New England). All three project as starters for the Broncos in 2010.

Of course, Denver started three outsiders on the defensive line in 2009 (Ronald Fields, Ryan McBean and Kenny Peterson), so employing retread imports to compensate for Denver's defensive-line shortcomings in the draft is hardly anything new for the club.

But it's got to be getting a little old.

"It's a difficult position to fill," conceded Broncos second-year coach Josh McDaniels at the NFL combine last month. "I think historically that has been the case."

True enough. For the Broncos, however, it's all but impossible, no matter if the coach is McDaniels or predecessor Mike Shanahan.

The last time the Broncos selected a player who made the Pro Bowl as a defensive lineman was in 1997, when they grabbed Trevor Pryce with the 28th pick in the first round. Elvis Dumervil earned a Pro Bowl nod in '09 after leading the league in sacks, but the fourth-year veteran, taken as an undersized 4-3 end in the 2006 draft, wasn't chosen for the all-star game until he switched to a hybrid rush linebacker in the 3-4 changeover under Nolan.

"They've had some turnover here," said Fields, a starter for all 16 games at nose tackle last season after signing as a free agent after four years in San Francisco (the five-year veteran likely will give way to Williams for the upcoming campaign).

Rarely, though, is the turnover due to an influx of young, homegrown linemen.

Since the 2000 season, the Broncos have used 27 different opening-day starters on the defensive line. Only seven were players originally drafted by the Broncos or signed as undrafted college free agents. Just twice in that 10-year stretch has Denver had more than two homegrown D-line starters in its Week 1 lineup. Five times in that span, the Broncos' Week 1 D-line starters who began their careers in Denver numbered either zero or one.

Pryce and Dumervil are the only homegrown defensive linemen to start consecutive season openers since 2000.

"It's been like a revolving door [of veteran linemen]," said tackle Gerard Warren, who was acquired from Cleveland in a 2005 trade, but who lasted just two years in Denver before being shipped to Oakland in 2007.

Blame it in large part on the glaring liabilities in drafting along the defensive line.

Including Dumervil and 2009 first-rounder Robert Ayers, who was chosen as an end but moved to outside linebacker in the 3-4 Nolan implemented last season, the Broncos have selected 15 defensive linemen in the draft since 2000. Only three of those players ever started more than eight games in a season, just Dumervil more than once. Seven of those draft picks are no longer in the league, and 10 logged fewer than five total starts in Denver. Seven never started a single contest during their Broncos' tenures.

Denver has suffered its share of poor luck with linemen in the draft -- such as the knee problems that have plagued end Jarvis Moss, limiting the 2007 first-round pick to one start in three seasons -- but the Broncos' track record has been nonetheless dismal.

Because of the obvious shortcomings in the draft, Denver imported 19 defensive-line veterans (11 in free agency and another eight via trades) from 2000-2009. In 2005, the Broncos added four linemen via trades, including three from the Cleveland Browns. Many of the newcomers fizzled as well, such as former No. 1 overall draft choice Courtney Brown; onetime first-rounders Daryl Gardener, Dewayne Robertson, Jimmy Kennedy, Ebenezer Ekuban, Marco Coleman, Ellis Johnson, and Warren; and notable players like Leon Lett, Lional Dalton, and John Engelberger.

So while free agency has slowed mostly to a waltz in its first two weeks, in Denver, it's pretty much been the annual line dance.

Len Pasquarelli, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com.