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31 Dec 2003

Fun With Sacks, Part II

by Michael Smith (2003 numbers added by Aaron Schatz)

Few certainties exist in the world of football, but this is one of them: You could assemble an offensive line with Anthony Munoz, Forrest Gregg, Joe DeLamielleure, Larry Allen, and Mike Webster, all in their primes, but if you put Rob Johnson behind them, he'd still find a way to get sacked.

Most observers think sacks are a function of the battle at the line of scrimmage.  When the offensive line wins the battle, the quarterback is able to throw his pass; when the defensive line wins, he isn't.

But what about the quarterback? Isn't he equally responsible for getting rid of the ball before the defense reaches him?  Last Monday, Football Outsiders took a look at how often a team took a sack based not on total sacks but on sack rate, the percentage of pass attempts that resulted in sacks.  Well, the best way to determine whether the quarterback or line is responsible is to see if different quarterbacks playing behind the same line have similar sack rates.  So I've looked at the 30 teams in the past three full seasons with more than one quarterback with 100 passes.  And I found that sack rates vary widely even when quarterbacks are playing behind the same line.  My feeling, based on these statistics, is that the quarterback is more important than the line.  And the Lions' quarterback, Joey Harrington, might be the best in history at avoiding sacks.  Then again, looking at his passing numbers, maybe he's just the quickest in history at throwing the ball away.

And then there's Johnson.  If you stayed up late enough for the season's final Monday night game, you saw him get sacked against the Packers. In 2000 he was sacked on 16% of his pass attempts.  Playing behind the same line, Doug Flutie was sacked on 4.3% of his attempts.  But Flutie is known for his smarts and his mobility.  Could it be that Johnson was playing behind a line whose weaknesses were masked by Flutie's skills?  Nope.  The next year, splitting time with Alex Van Pelt (who is known neither for smarts nor mobility), Johnson was sacked at more than three times the rate of his fellow quarterback.

I should acknowledge that these statistics have some weaknesses.  I haven't adjusted for situation or defense faced, and I haven't examined how much the personnel on these offensive lines changed as the season wore on.  Nonetheless, the statistics reveal that when quarterbacks are sacked, they can blame themselves as much as their linemen.

(Aaron's note: After Mike sent me this article, I decided to hold off on publishing it until I could run the 2003 data. The 2003 numbers include both sack rate and adjusted sack rate, which takes into account down, distance, and opponent.)

The following tables include all teams that had two or three quarterbacks with 100 pass attempts each, plus both 2003 Jaguar quarterbacks just for the heck of it.

 



2003
QB Team Passes Sacks Rate Adj. Rate
Blake ARI 384 18 4.7% 4.5%
McCown ARI 192 24 12.5% 12.1%
D. Johnson ATL 260 18 6.9% 6.9%
Kittner ATL 119 5 4.2% 3.4%
Vick ATL 110 10 9.1% 9.3%
Boller BAL 237 16 6.8% 6.7%
Wright BAL 192 14 7.3% 6.7%
Stewart CHI 272 24 8.8% 9.1%
Chandler CHI 202 12 5.9% 5.8%
Holcomb CLE 318 18 5.7% 5.7%
Couch CLE 222 19 8.6% 8.4%
Plummer DEN 313 14 4.5% 5.2%
Kanell DEN 105 2 1.9% 1.4%
Carr HOU 313 15 4.8% 4.7%
Banks HOU 112 12 10.7% 10.3%
Leftwich JAC 437 18 4.1% 3.9%
Brunell JAC 92 9 9.8% 9.3%
Fiedler MIA 333 19 5.7% 5.7%
Griese MIA 141 12 8.5% 8.3%
Collins NYG 526 27 5.1% 4.8%
Palmer NYG 130 15 11.5% 11.1%
Pennington NYJ 320 24 7.5% 7.2%
Testaverde NYJ 203 6 3.0% 2.8%
Mirer OAK 241 21 8.7% 8.3%
Gannon OAK 240 17 7.1% 7.5%
Brees SDG 374 21 5.6% 5.7%
Flutie SDG 175 7 4.0% 4.4%
Garcia SFO 412 22 5.3% 5.7%
Rattay SFO 125 7 5.6% 5.1%
Ramsey WAS 368 30 8.2% 7.5%
T. Hasselbeck WAS 186 9 4.8% 4.8%


2001
QB Team Passes Sacks Rate
ATL Chandler 365 41 11.2%
ATL Vick 113 21 18.5%
BUF Van Pelt 307 14 4.6%
BUF R. Johnson 216 31 14.4%
CHI Miller 395 11 2.8%
CHI Matthews 129 6 4.7%
DET Batch 341 33 9.7%
DET T. Detmer 151 12 7.9%
DET McMahon 115 21 18.3%
SEA M. Hasslebeck 321 38 11.8%
SEA Dilfer 122 10 8.2%


2002
QB Team Passes Sacks Rate
BAL Blake 295 30 10.2%
BAL Redman 182 11 6.0%
CHI Miller 314 16 5.1%
CHI Chandler 161 23 14.3%
CLE Couch 443 30 6.8%
CLE Holcomb 106 5 4.7%
DAL Hutchinson 250 34 13.6%
DAL Carter 221 19 8.6%
DEN Griese 436 34 7.8%
DEN Beuerlein 117 12 10.3%
DET Harrington 429 8 1.9%
DET McMahon 147 12 8.2%
MIA Fiedler 292 13 4.5%
MIA Lucas 160 12 7.5%
PHI McNabb 361 28 7.8%
PHI Feeley 154 7 4.5%
PIT Maddox 377 26 6.9%
PIT Stewart 166 7 4.2%
SEA M. Hasselbeck 419 26 6.2%
SEA Dilfer 168 7 4.2%
STL Warner 220 21 9.5%
STL Bulger 214 12 5.6%
STL Martin 195 10 5.1%
WAS Matthews 237 9 3.8%
WAS Ramsey 227 18 7.9%


2000
QB Team Passes Sacks Rate
ATL Chandler 331 40 12.1%
ATL Kanell 116 8 6.9%
BAL Banks 274 20 7.3%
BAL Dilfer 226 23 10.2%
BUF R. Johnson 306 49 16.0%
BUF Flutie 231 10 4.3%
CHI McNown 280 27 9.6%
CHI Matthews 178 5 2.8%
CIN Smith 267 36 13.5%
CIN Mitchell 187 16 8.6%
CLE Couch 215 10 4.7%
CLE Pederson 210 17 8.1%
DAL Aikman 262 13 5.0%
DAL Cunningham 125 8 6.4%
DEN Griese 336 17 5.1%
DEN Frerotte 232 12 5.2%
NOR Blake 302 24 7.9%
NOR Brooks 194 15 7.7%
PIT Stewart 289 30 10.4%
PIT Graham 148 13 8.8%
SDG Leaf 322 31 9.6%
SDG Harbaugh 202 14 6.9%
STL Warner 347 20 5.8%
STL Green 240 24 10.0%
WAS B. Johnson 365 20 5.5%
WAS George 194 12 6.2%

Posted by: Michael David Smith on 31 Dec 2003

1 comment, Last at 13 Jun 2005, 9:24pm by Richie

Comments

1
by Richie (not verified) :: Mon, 06/13/2005 - 9:24pm

I see that Chris Chandler had sack % around 12% the first 3 years of the study, then it suddenly dropped to 5%, yet his QB-mate in Chicago that year (Kordell Stewart) was getting sacked 9% of the time (after only 4% the year before).