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NFL Free Agency

Posted by Chase Stuart on September 16, 2009

Tim Truemper, frequent commenter here on the P-F-R blog, recently e-mailed us with a question that had been bugging him: how much variance is there among teams with respect to roster stability in the free agency era?

Essentially, Tim wants to know if certain teams do a great job at retaining their guys and if certain teams do a poor job. That's a question that AV can help us answer.

I looked at every team from 1993 (the inception of free agency) to 2007, a fifteen year period. I recorded the AV of each player on each team for those fifteen seasons. Then, I noted whether each player was playing for that same team in the following season, was playing for no team, or was playing for another team. Generally, when a player is not on a team the following season, it's because of injury, retirement or lack of talent (and, occasionally, incarceration); that's not something that's affected by free agency, though, so I'm only going to focus on players who switch teams in the off-season. For simplicity's purposes, I've ignored the 1995 Browns as opposed to seeing if those players were on the '96 Ravens; I've also split the Browns into the old Browns and new Browns. I did not do the same things for other franchises that moved cities, and I don't have a terribly persuasive justification for that.

The table below shows the best 15 players to switch teams in the free agency era; obviously, some of these players will have left via trade.

Age	Year	Tm	AV	Newtm	
27	2005	clt	19	crd	Edgerrin James
25	1994	sfo	19	phi	Ricky Watters
29	2006	rav	18	nwe	Adalius Thomas
25	1998	clt	18	ram	Marshall Faulk
34	1996	car	18	sfo	Kevin Greene
31	2002	phi	17	jax	Hugh Douglas
24	2001	phi	17	was	Jeremiah Trotter
28	2000	sfo	17	rai	Charlie Garner
27	1997	sfo	17	was	Dana Stubblefield
26	1996	pit	17	sea	Chad Brown
25	2007	kan	16	min	Jared Allen
22	2003	den	16	was	Clinton Portis
28	1997	pit	16	oti	Yancey Thigpen
26	2007	nwe	15	phi	Asante Samuel
26	2005	sdg	15	nor	Drew Brees
32	1999	dal	15	was	Deion Sanders
29	1994	cle	15	den	Michael Dean Perry

So how do we measure roster turnover? There are lots of ways to measure turnover, and I don't claim that mine is the best one; just the one that's most intuitive to me. We care more about a guy like Marshall Faulk leaving than when a third string defensive tackle switches teams. So I calculated the total team AV for each team in each season, and then measured what percentage of team AV was credited to players who were on different teams the next year.

Twelve teams (out of 460) retained 97% of their team AV, led by the 1999 Colts. That team retained the players who accounted for 225 of the team's 227 points of AV in '99, losing only Bradford Banta and Tony McCoy in the off-season. Six teams retained fewer than 70% of their team AV, with the '01 Ravens being the only squad that fell below 60%. Two years after winning the Super Bowl, the '02 Ravens were decimated; six of the nine players who had 9 or more points of AV in '01 switched teams: Rod Woodson and Sam Adams went West to Oakland and made the Super Bowl again; Jamie Sharper went to the expansion Texans; Shannon Sharpe proved you can go home again; Corey Harris went to the Lions and Qadry Ismail went to the Colts. Additionally, Elvis Grbac retired, and he doesn't even count for purposes of this study. Further decimating the defense, Rob Burnett and Duane Starks went to Miami and Arizona, respectively.

I then averaged the percentage loss for each team over the 15-year period. The table below summarizes the results; the Texans and Bengals lead all franchises with the least amount of "voluntary" turnover. Things are very tight at the bottom, with the Eagles, Ravens, Saints and Browns having the most turnover. "Cle1" represents the old Browns; "Cle2" the new ones. For each franchise, in addition to the average turnover, I've listed the teams with the smallest and biggest turnover from '93 to '07. I've also listed the best player lost in the period by each franchise, as measured by AV in his last season with the team. I only listed one player for space reasons, and often there was a tie (three or four guys leaving with an AV of 9, for example); a player was randomly selected in that event.

	Avg	Smallest Turn   Biggest Turn    Best player
htx	90.4%	htx2003-95.9	htx2005-81.3	David Carr
cin	89.6%	cin1993-97.2	cin1998-79.7	Jeff Blake
rai	88.4%	rai1998-94.7	rai2003-73.1	Kerry Collins
clt	87.9%	clt1999-99.1	clt1998-74.5	Edgerrin James
kan	87.7%	kan2002-96.4	kan2007-76.9	Jared Allen
nwe	87.4%	nwe1995-98.3	nwe1994-76.2	Asante Samuel
sea	87.4%	sea2002-99.0	sea1999-79.5	Steve Hutchinson
jax	87.1%	jax2004-93.5	jax2001-71.1	Gary Walker
pit	86.8%	pit2006-95.5	pit1996-71.3	Chad Brown
gnb	86.7%	gnb1996-95.0	gnb2005-76.0	Brett Favre
dal	86.5%	dal2006-96.8	dal2003-78.5	Deion Sanders
tam	86.2%	tam2002-93.3	tam2003-74.7	Hardy Nickerson
buf	86.0%	buf1998-96.8	buf2000-75.5	Peerless Price
was	86.0%	was2007-98.1	was1994-72.0	Antonio Pierce
sdg	85.9%	sdg2004-98.3	sdg1993-73.3	Drew Brees
det	85.8%	det2000-93.7	det1993-73.1	Lomas Brown
den	85.8%	den1995-93.1	den1994-76.6	Clinton Portis
car	85.6%	car2006-92.8	car2003-79.6	Kevin Greene
oti	85.6%	oti2002-94.5	oti2004-72.9	Jon Runyan
atl	85.5%	atl2002-94.1	atl1993-71.7	Tony Martin
crd	85.1%	crd2005-95.5	crd1993-66.1	Calvin Pace
nyg	85.1%	nyg1997-97.6	nyg1993-73.4	Greg Jackson
min	85.0%	min2007-95.1	min1993-69.9	Chris Doleman
chi	84.2%	chi2005-99.1	chi1996-73.6	Jeff Graham
sfo	84.1%	sfo2006-94.0	sfo2003-69.5	Ricky Watters
ram	84.0%	ram2006-93.5	ram1998-69.4	Trent Green
mia	84.0%	mia1998-94.1	mia1995-70.4	Adewale Ogunleye
nyj	84.0%	nyj1996-92.9	nyj1994-65.7	Laveranues Coles
cle2	83.9%	cle2007-94.7	cle2004-70.1	Antonio Bryant
rav	83.8%	rav2007-97.6	rav2001-57.0	Adalius Thomas
nor	83.8%	nor2006-95.6	nor2001-61.2	Ricky Williams
phi	83.7%	phi2000-95.2	phi1995-65.1	Hugh Douglas
cle1	82.6%	cle1993-85.0	cle1994-80.2	Michael Dean Perry

This entry was posted on Wednesday, September 16th, 2009 at 1:13 pm and is filed under History, Statgeekery. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.