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The Purple People Eaters

Last Monday, I provided some initial thoughts on the relative values of completion and passing first down percentage. The next day, I looked at how teams with disparate performances in those two metrics. And last Wednesday, I looked at the best passing offenses in NFL history in first down rate on passing plays.

Today? A look at the best pass defenses at preventing first downs.  This time, I am also going to era adjust these ratings. In 1969, the Vikings faced 459 pass plays (410 pass attempts, 49 sacks) but allowed only 88 passing first downs. That’s a remarkable rate of just 19.2%, the best since World War II.   It’s also the best rate on an era-adjusted basis.  The league average in the NFL in 1969 was 29.0%, which means this iteration of the Purple People Eaters was 9.8% better than league average, the highest differential ever.

RkTmYear1D PassPass AttSk1D/PPLgAvgDiff
1MIN1969884104919.2%29%-9.8%
2GNB1963873783920.9%29.5%-8.6%
3MIN1971884052720.4%28.1%-7.7%
4NYJ20091285013224%31.7%-7.7%
5PHI1954843454321.6%29.3%-7.6%
6OAK19671034596719.6%27.2%-7.6%
7GNB1962943554223.7%30.9%-7.3%
8PIT1975973964322.1%29.2%-7.1%
9PIT1974833395221.2%28.3%-7.1%
10ATL1977763204221%28%-7%
11.5GNB1967783372921.3%28.2%-6.8%
11.5RAM19671044454321.3%28.2%-6.8%
13TAM20021315104323.7%30.5%-6.8%
14PHI1949683034519.5%26.3%-6.8%
15CHI19841224357224.1%30.7%-6.7%
16MIA1973783224521.3%27.9%-6.6%
17CLE1954733002222.7%29.3%-6.6%
18DEN20041304843824.9%31.5%-6.6%
19MIN1970893674921.4%27.9%-6.5%
20CHI1958843274722.5%28.9%-6.4%
21PHI20081445254825.1%31.5%-6.4%
22DEN20151625735225.9%32.3%-6.4%
23CHI19621013634824.6%30.9%-6.4%
24BAL20001355283524%30.3%-6.3%
25TAM19991445734323.4%29.7%-6.3%
26MIN1975933604622.9%29.2%-6.3%
27TAM19791114364023.3%29.6%-6.2%
28CHI19851415226424.1%30.3%-6.2%
29DET19621053675724.8%30.9%-6.2%
30PIT20081495335125.5%31.5%-6%
31DET1976763132822.3%28.2%-6%
32ATL19781134444723%29%-5.9%
33DAL20031274923224.2%30.2%-5.9%
34WAS19911515485025.3%31.2%-5.9%
35MIN19891404887125%30.9%-5.9%
36RAM19801415105624.9%30.7%-5.8%
37DAL1977943705322.2%28%-5.8%
38OAK19691074224722.8%28.6%-5.8%
39STL19661094435222%27.8%-5.7%
40PHI19911334675525.5%31.2%-5.7%
41HOU20121675814426.7%32.4%-5.7%
42GNB20081415182725.9%31.5%-5.6%
43MIN1972823312123.3%28.9%-5.6%
44GNB20021435314324.9%30.5%-5.6%
45HOU1969933713223.1%28.6%-5.5%
46NOR19911394915025.7%31.2%-5.5%
47CHI20061595814025.6%31.1%-5.5%
48HOU1976903455022.8%28.2%-5.5%
49CHI1959913333224.9%30.4%-5.5%
50JAX20061435233525.6%31.1%-5.4%
51OAK1973923704022.4%27.9%-5.4%
52WAS1976913544422.9%28.2%-5.4%
53DEN1971913564422.8%28.1%-5.4%
54CLE1957662422624.6%29.9%-5.3%
55BAL19991585994924.4%29.7%-5.3%
56NYG19611103865025.2%30.5%-5.3%
57BAL20031445314724.9%30.2%-5.2%
58RAM19751033874324%29.2%-5.2%
59SFO1952763423620.1%25.3%-5.2%
60CIN1972923503823.7%28.9%-5.2%
61KAN19691114264823.4%28.6%-5.2%
62DEN19891425044725.8%30.9%-5.1%
63PIT1976963734123.2%28.2%-5.1%
64RAI19841475086425.7%30.7%-5%
65PHI19811375074025%30.1%-5%
66BUF20141715595427.9%32.9%-5%
67PHI1955692722723.1%28.1%-5%
68BUF19801204333325.8%30.7%-5%
69CHI20051535504125.9%30.9%-5%
70TEN20071655694027.1%32%-4.9%
71MIN19881324803725.5%30.4%-4.9%
72CIN20131786144327.1%32%-4.9%
73NYG1959853042925.5%30.4%-4.9%
74RAM1977943703623.2%28%-4.9%
75MIA1982652262925.5%30.3%-4.8%
76CHI1963963533624.7%29.5%-4.8%
77SFO19761023746123.4%28.2%-4.8%
78PHI19791254594524.8%29.6%-4.8%
79PIT1956662342525.5%30.2%-4.8%
80GNB19961515443726%30.7%-4.7%
81CLE1973793122923.2%27.9%-4.7%
82CLE1951813305421.1%25.8%-4.7%
83NYG20101595394627.2%31.9%-4.7%
84TEN20081665754426.8%31.5%-4.7%
85PIT1973913593323.2%27.9%-4.7%
86NYG1958803111924.2%28.9%-4.7%
87PHI20021605635625.8%30.5%-4.6%
88RAM19851555485625.7%30.3%-4.6%
89WAS20071746023327.4%32%-4.6%
90MIN1977803123023.4%28%-4.6%
91PHI19921465175525.5%30.1%-4.6%
92PIT20111565303527.6%32.2%-4.6%
93TEN20001344665525.7%30.3%-4.6%
94RAM1973873284523.3%27.9%-4.6%
95NYG19631063685724.9%29.5%-4.5%
96BAL20061515096026.5%31.1%-4.5%
97PIT19901304603426.3%30.8%-4.5%
98STL19611123894226%30.5%-4.5%
99SFO19861696045125.8%30.3%-4.5%
100DEN19971455264425.4%29.9%-4.5%
101SEA20131565244427.5%32%-4.5%
102CHI1967983843023.7%28.2%-4.5%
103OAK19681134464922.8%27.3%-4.5%
104PIT19781194424424.5%29%-4.5%
105BAL20081525283427%31.5%-4.5%
106BUF20131705615727.5%32%-4.5%
107SEA1982682461725.9%30.3%-4.4%
108NOR19921465115725.7%30.1%-4.4%
109NYG19901394963026.4%30.8%-4.4%
110NYG1957642262525.5%29.9%-4.4%
111HOU20161575223128.4%32.8%-4.4%
112PIT20071585363627.6%32%-4.4%
113CLE1956622261425.8%30.2%-4.4%
114GNB19611174143426.1%30.5%-4.4%
115HOU19951575533026.9%31.3%-4.4%
116WAS19851344655225.9%30.3%-4.4%
117CHI1960842915324.4%28.8%-4.4%
118DEN20161695524228.5%32.8%-4.4%
119PIT19941565325526.6%30.9%-4.3%
120CRD1956792871825.9%30.2%-4.3%
121PIT1959802852226.1%30.4%-4.3%
122OAK19751133985524.9%29.2%-4.2%
123TAM20041314364527.2%31.5%-4.2%
124STL20011535414526.1%30.3%-4.2%
125NYJ19981505443625.9%30.1%-4.2%
126SFO19871324673726.2%30.4%-4.2%
127DAL19841555275726.5%30.7%-4.2%
128BUF19601094293623.4%27.6%-4.2%
129PHI1956692432226%30.2%-4.2%
130CHI19811445253125.9%30.1%-4.2%
131SFO19971455095425.8%29.9%-4.2%
132DET1960943542824.6%28.8%-4.2%
133ARI20111745784228.1%32.2%-4.1%
134NYG19871485085526.3%30.4%-4.1%
135GNB19971565634125.8%29.9%-4.1%
136NYG20161916303528.7%32.8%-4.1%
137HOU19861374903226.2%30.3%-4.1%
138CHI19861515136226.3%30.3%-4.1%
139PIT19791354804925.5%29.6%-4%
140WAS19771023804524%28%-4%
141BAL1971953613324.1%28.1%-4%
142DAL19701053994123.9%27.9%-4%
143PHI19801575434426.7%30.7%-4%
144NYJ19681044034323.3%27.3%-4%
145RAM19881665715626.5%30.4%-3.9%
146DET1967853123924.2%28.2%-3.9%
147SDG19981495303926.2%30.1%-3.9%
148SFO19811445143626.2%30.1%-3.9%
149WAS20041535154027.6%31.5%-3.9%
150SDG19791324724225.7%29.6%-3.9%
151PHI20001595525026.4%30.3%-3.9%
152WAS20001344624526.4%30.3%-3.9%
153PHI20041655504727.6%31.5%-3.8%
154PHI20061545254027.3%31.1%-3.8%
155SDG19801565196026.9%30.7%-3.8%
156MIN19931394784526.6%30.4%-3.8%
157CAR20151986504428.5%32.3%-3.7%
158BAL20111665354828.5%32.2%-3.7%
159NYJ19951494974327.6%31.3%-3.7%
160BAL19681194324524.9%28.7%-3.7%
161DET19631093784525.8%29.5%-3.7%
162HOU20111665384428.5%32.2%-3.7%
163CHI1957963066026.2%29.9%-3.7%
164MIA1972963483325.2%28.9%-3.7%
165SFO1951843532722.1%25.8%-3.7%
166PIT20041464844127.8%31.5%-3.7%
167DEN19761043913224.6%28.2%-3.7%
168PHI20011505174526.7%30.3%-3.7%
169CLE19871344673426.7%30.4%-3.7%
170PHI19861565325326.7%30.3%-3.6%
171KAN19951785964727.7%31.3%-3.6%
172RAM19781133994725.3%29%-3.6%
173PIT19661053973824.1%27.8%-3.6%
174DEN20031414953626.6%30.2%-3.6%
175CAR19961675566027.1%30.7%-3.6%
176DET1956842971826.7%30.2%-3.6%
177NYG19811565444426.5%30.1%-3.6%
178MIN1973993773024.3%27.9%-3.6%
179CLE1955833231524.6%28.1%-3.6%
180CHI19881585454326.9%30.4%-3.5%
181RAM19811284394326.6%30.1%-3.5%
182CAR20061495004127.5%31.1%-3.5%
183SFO19961645584527.2%30.7%-3.5%
184BAL19701204524124.3%27.9%-3.5%
185MIN1976913234524.7%28.2%-3.5%
186BAL20011615554526.8%30.3%-3.5%
187NYG19621364504627.4%30.9%-3.5%
188PIT20161845903829.3%32.8%-3.5%
189DET20121675443428.9%32.4%-3.5%
190GNB19661063904724.3%27.8%-3.5%
191DEN19961655664027.2%30.7%-3.5%
192RAM1950883853720.9%24.3%-3.5%
193CAR20021555225227%30.5%-3.5%
194SFO20091765804428.2%31.7%-3.5%
195PIT20101825934828.4%31.9%-3.5%
196GNB20101635274728.4%31.9%-3.5%
197CIN19751073892725.7%29.2%-3.5%
198DET19691013504625.5%29%-3.5%
199GNB1964913184525.1%28.5%-3.5%
200DEN19811424973626.6%30.1%-3.4%

The table above shows the top 200 pass defenses at preventing first downs.

  • Since 2010, the best pass defenses were, in order, the 2015 Broncos, 2012 Texans, and 2014 Bills.
  • In the ’00s, the best pass defenses were the 2009 Jets, 2002 Bucs, 2004 Broncos, 2008 Eagles, 2000 Ravens, and 2008 Steelers.
  • In the 1990s, the best pass defenses were the 1999 Bucs, 1991 Redskins, 1991 Eagles, 1991 Saints, and 1999 Ravens.
  • The ’80s? The ’84 Bears, ’85 Bears, ’89 Vikings, ’80 Rams, ’89 Broncos, and ’84 Raiders.
  • The ’70s? The ’71 Vikings, ’75 Steelers, ’74 Steelers, ’77 Falcons (of course), ’83 Dolphins, ’70 Vikings, ’75 Vikings, and ’79 Bucs.
  • The ’60s? The ’69 Vikings, ’63 Packers, ’67 Raiders, ’62 Packers, ’67 Packers, ’67 Rams, and ’62 Bears and Lions.
  • The ’50s? The ’54 Eagles, ’54 Browns, ’58 Bears, ’59 Bears, ’57 Browns, and ’52 49ers.

As always, please leave your thoughts in the comments.

  • sacramento gold miners

    It was interesting to see how the Vikings had issues with Kansas City’s shifting offense in the SB that season. Obviously, the film study and scout team for Minnesota came up short when trying to replicate the formation movement. Another factor was how successful the Chiefs were in passing on early downs. This may sound strange today, but short, quick passes on first down were unusual in the 1960s. Minnesota’s corners were ill-equipped to handle the likes of Otis Taylor. The Chiefs registered 18 first downs in SB4, the second most allowed by the Vikings in the entire season.

  • I’m pretty surprised the 2013 Seahawks don’t make the top-100, given that they had top-20 pass defense all-time according to Football Outsiders’ metrics. Then again, their Achilles’ Heel has always been 3rd down conversions. I don’t know what it is, but there seems to be something that makes them substantially on 3rd down than on 1st and 2nd down. It’s been this way since they got good in 2012.

    Last week Sunday is a perfect example. They hold Goff to 5.6 yards-per-attempt, a sub-50% completion percentage, and turn him over three times, and yet he goes 8 for 15 on third down conversions. ¯_(ツ)_/¯

  • Gotta love any mention of the 1977 Falcons!

  • Assuming I counted correctly, there are 17 Steelers teams, 16 Eagles teams, 14 Bears teams, and 11 each Giants and Vikings. The Eagles seem surprising but otherwise those are the franchises one would expect to have the most entries.
    For my team, it’s shocking that the ’04 Denver defense outranks the ’15 defense. The ’04 defense was really good and that was by far the best year Champ Bailey played in Denver, but I would not have guessed it would rank nearly as high as 2015. That ’04 team was really good at being good in ways that weren’t too obvious.

  • kevin trammo

    So the 2009 Jets are 4th all time in preventing first downs via the pass. In addition allowed an unheard of 8 TD passes the entire season, yet Charles Woodson who played on a Packer D that allowed 29 TD passes and even allowed a 500 yard passing game was defensive MVP and not Revis. Yeah, OK!