NFL offenses and defenses are not mirror images of each other. The gap between the best and worst offenses is generally bigger than the spread on the defensive side of the ball. And strength of schedule is more likely to play a key role when it comes to determine the best and worst defenses, too. Today’s post is a two-parter: in Part I, we look at some data on the best and worst teams in the modern era, while Part II analyzes the above claims.

Ranking offenses (or defenses) isn’t easy. I don’t like using yards, which is misleading in a lot of ways. Points scored sounds good, but non-offensive scores and other big plays on defense and special teams can make that metric less telling. There are some very good advanced metrics, but they don’t help us if we want to go back to the 1970s. So I simply used offensive touchdowns scored to rank the offenses and offensive touchdowns allowed to rank the defenses. And since I’m going to go back to 1970, I’ll be comparing each unit to the league average in that season.

Part I – Team Rankings

In addition, I’m going to adjust the offenses and defenses for strength of schedule. I’ll be doing this in an iterative way just like I do with the SRS. Listed below are the top 100 teams since 1970 in terms of offensive touchdowns per game over average (and in addition to adjusting for strength of schedule, I’ve pro-rated the non-16 game seasons to 16 games). The first line shows the 2007 Patriots, who scored 67 offensive touchdowns when the league average was 34.6. Therefore, NE gets credit for being 32.4 touchdowns over average. The Patriots’ schedule was actually difficult (once you adjust for the fact that their opponents faced New England) — it cost the offense nearly 2 touchdowns — so their final rating is +34.4.

Rk	Tm	Year	G	OTD	LGAVG	TDovAVG	SOS	RATING
1	NWE	2007	16	67	34.6	32.4	1.9	34.4
2	STL	2000	16	63	33.7	29.3	-0.8	28.5
3	BUF	1975	14	61.7	37.2	24.5	2.6	27.1
4	MIA	1984	16	67	36.6	30.4	-3.4	27
5	GNB	2011	16	63	35.8	27.2	-1	26.2
6	IND	2004	16	61	35.9	25.1	1	26.1
7	SFO	1998	16	60	34.6	25.4	0.4	25.9
8	KAN	2004	16	58	35.9	22.1	2.9	25
9	SFO	1993	16	55	29.3	25.7	-0.8	24.9
10	NWE	2010	16	56	35.9	20.1	4.6	24.7
11	SFO	1994	16	60	33	27	-2.6	24.4
12	STL	2001	16	57	32.3	24.7	-0.8	23.9
13	NOR	2011	16	62	35.8	26.2	-2.5	23.7
14	DEN	1998	16	58	34.6	23.4	0.2	23.6
15	SDG	1982	9	60.4	35	25.5	-1.9	23.6
16	SDG	1981	16	60	36.9	23.1	0.2	23.3
17	MIN	1998	16	58	34.6	23.4	-0.2	23.3
18	SDG	2006	16	56	33.5	22.5	0.2	22.7
19	KAN	2003	16	56	33.8	22.2	0.2	22.5
20	SDG	1985	16	57	37.2	19.8	1.5	21.3
21	SFO	1987	15	58.7	37	21.6	-0.3	21.3
22	BAL	1976	14	57.1	34.5	22.6	-1.4	21.2
23	DAL	1971	14	53.7	31.7	22	-1	21
24	NOR	2009	16	55	35.6	19.4	1.5	20.9
25	BUF	1991	16	55	31	24	-3.1	20.8
26	NYJ	1982	9	51.6	35	16.6	4.2	20.8
27	OAK	1976	14	53.7	34.5	19.2	1.3	20.5
28	WAS	1991	16	51	31	20	0.3	20.3
29	WAS	1983	16	59	37.9	21.1	-1	20.1
30	NWE	2011	16	57	35.8	21.2	-1.2	20
31	SFO	1992	16	51	30.3	20.7	-1.5	19.2
32	DAL	1980	16	56	37	19	-0.2	18.8
33	MIA	1986	16	55	35.3	19.8	-1.2	18.5
34	CIN	1988	16	55	35	20	-1.6	18.4
35	NOR	2008	16	54	35.1	18.9	-0.6	18.4
36	KAN	2002	16	53	36.1	16.9	1.3	18.2
37	SFO	1991	16	48	31	17	1.2	18.2
38	SDG	2005	16	49	33.6	15.4	2.6	18
39	OAK	1977	14	46.9	30.2	16.7	0.8	17.4
40	DAL	2007	16	50	34.6	15.4	1.9	17.3
41	WAS	1999	16	49	33.2	15.8	0.9	16.7
42	SDG	2004	16	53	35.9	17.1	-0.7	16.5
43	PIT	1979	16	51	36.6	14.4	1.9	16.3
44	IND	2007	16	51	34.6	16.4	-0.2	16.2
45	SEA	2005	16	54	33.6	20.4	-4.3	16.1
46	IND	2006	16	48	33.5	14.5	1.6	16.1
47	GNB	1996	16	48	33	15	0.9	15.9
48	DAL	1983	16	52	37.9	14.1	1.7	15.8
49	STL	1999	16	55	33.2	21.8	-6	15.8
50	CIN	1986	16	49	35.3	13.8	1.9	15.6
51	NWE	2009	16	47	35.6	11.4	4.2	15.6
52	OAK	1975	14	53.7	37.2	16.5	-1	15.6
53	OAK	2000	16	51	33.7	17.3	-1.7	15.5
54	OAK	1972	14	49.1	33.8	15.4	-0.1	15.3
55	IND	2000	16	47	33.7	13.3	1.9	15.1
56	GNB	2003	16	50	33.8	16.2	-1.2	15
57	MIA	1985	16	50	37.2	12.8	2.2	15
58	CIN	2005	16	47	33.6	13.4	1.5	14.9
59	PIT	1976	14	49.1	34.5	14.6	0.3	14.9
60	DAL	1973	14	49.1	31.1	18	-3.2	14.8
61	IND	2009	16	50	35.6	14.4	0.2	14.7
62	STL	1984	16	49	36.6	12.4	2.3	14.6
63	DAL	1977	14	44.6	30.2	14.4	0.3	14.6
64	OAK	1974	14	49.1	32.6	16.6	-2.1	14.4
65	SFO	1984	16	53	36.6	16.4	-2	14.4
66	RAM	1973	14	45.7	31.1	14.6	-0.2	14.4
67	DAL	1978	16	47	32.9	14.1	0.2	14.3
68	CIN	1989	16	49	34.6	14.4	-0.1	14.2
69	MIN	2009	16	53	35.6	17.4	-3.3	14.1
70	MIA	1974	14	49.1	32.6	16.6	-2.5	14.1
71	CIN	1985	16	51	37.2	13.8	0.3	14.1
72	BAL	1996	16	44	33	11	3.1	14.1
73	MIN	1999	16	45	33.2	11.8	2.2	14
74	SFO	2001	16	48	32.3	15.7	-1.7	14
75	IND	2003	16	45	33.8	11.2	2.8	14
76	PIT	1977	14	42.3	30.2	12.1	1.7	13.8
77	RAM	1989	16	48	34.6	13.4	0.4	13.8
78	RAM	1988	16	47	35	12	1.7	13.7
79	DET	2011	16	50	35.8	14.2	-0.5	13.7
80	MIA	1977	14	45.7	30.2	15.5	-2	13.5
81	GNB	1995	16	48	34.9	13.1	0.4	13.4
82	DET	1995	16	49	34.9	14.1	-0.8	13.2
83	MIN	2000	16	47	33.7	13.3	-0.1	13.1
84	BAL	1975	14	53.7	37.2	16.5	-3.5	13.1
85	NWE	1974	14	45.7	32.6	13.1	-0.1	13
86	RAI	1982	9	51.6	35	16.6	-3.7	12.9
87	SDG	1979	16	49	36.6	12.4	0.5	12.9
88	DAL	1994	16	45	33	12	0.8	12.9
89	NWE	2006	16	45	33.5	11.5	1.3	12.8
90	BUF	1990	16	48	34	14	-1.2	12.8
91	NWE	1976	14	48	34.5	13.5	-0.8	12.6
92	IND	2005	16	49	33.6	15.4	-2.9	12.5
93	DAL	1995	16	47	34.9	12.1	0.5	12.5
94	JAX	2007	16	46	34.6	11.4	1.1	12.5
95	OAK	1999	16	42	33.2	8.8	3.6	12.5
96	HOU	1990	16	47	34	13	-0.6	12.4
97	OAK	1971	14	45.7	31.7	14	-1.6	12.4
98	SFO	1970	14	43.4	31.6	11.8	0.6	12.4
99	DET	1972	14	44.6	33.8	10.8	1.5	12.4
100	CIN	1975	14	49.1	37.2	12	0.4	12.3

Seeing the ’75 Bills on there was a little shocking to me,, but Buffalo led the league in passing touchdowns, points, yards and rushing yards and ranked 3rd in rushing touchdowns, against a difficult schedule in a defensive era. The 1999 Rams were 21.8 touchdowns over average on offense, but they faced an absurdly easy schedule, one them gave them approximately 6 extra touchdowns. In fact, the three most offense-friendly schedules since 1970 belong to the ’99 Rams, ’72 Dolphins and ’82 49ers. Seven of Peyton Manning’s Colts teams are on there, including an incredible five-year stretch beginning in 2003. The 2009 and 2010 Patriots faced two of the hardest schedules since the merger among elite offenses.

We can also look at the worst 100 offenses:

Rk	Tm	Year	G	OTD	LGAVG	TDovAVG	SOS	RATING
1221	TAM	1977	14	8	30.2	-22.2	-2.2	-24.4
1220	OAK	2006	16	12	33.5	-21.5	-0.7	-22.2
1219	STL	2009	16	16	35.6	-19.6	-2	-21.6
1218	CHI	2004	16	19	35.9	-16.9	-4.6	-21.5
1217	ARI	2010	16	19	35.9	-16.9	-3.5	-20.5
1216	ATL	1974	14	11.4	32.6	-21.1	1.5	-19.7
1215	PHI	1998	16	17	34.6	-17.6	-2.1	-19.7
1214	GNB	1977	14	12.6	30.2	-17.6	-1.9	-19.5
1213	IND	1991	16	13	31	-18	-1.4	-19.4
1212	TAM	1976	14	16	34.5	-18.5	-0.9	-19.4
1211	KAN	2011	16	18	35.8	-17.8	-1.5	-19.3
1210	NYG	1983	16	21	37.9	-16.9	-1.7	-18.6
1209	HOU	2002	16	17	36.1	-19.1	0.5	-18.6
1208	CAR	2010	16	16	35.9	-19.9	1.4	-18.6
1207	PHI	1972	14	13.7	33.8	-20	1.9	-18.1
1206	SEA	1992	16	13	30.3	-17.3	-0.5	-17.8
1205	STL	2008	16	19	35.1	-16.1	-1.3	-17.4
1204	OAK	2009	16	17	35.6	-18.6	1.3	-17.3
1203	SDG	1997	16	17	33.4	-16.4	-0.7	-17.1
1202	BUF	1985	16	22	37.2	-15.2	-1.7	-16.9
1201	STL	2011	16	16	35.8	-19.8	3	-16.8
1200	SFO	2005	16	17	33.6	-16.6	-0.2	-16.8
1199	NYG	1996	16	18	33	-15	-1.2	-16.2
1198	NOR	1975	14	19.4	37.2	-17.8	1.6	-16.2
1197	ATL	2000	16	20	33.7	-13.7	-2.2	-16
1196	SDG	1988	16	22	35	-13	-2.7	-15.7
1195	CLE	2000	16	16	33.7	-17.7	2.1	-15.6
1194	IND	1993	16	14	29.3	-15.3	-0.2	-15.5
1193	SDG	1998	16	22	34.6	-12.6	-2.9	-15.5
1192	GNB	1974	14	17.1	32.6	-15.4	0.1	-15.4
1191	CIN	1993	16	14	29.3	-15.3	0.2	-15.2
1190	WAS	2004	16	24	35.9	-11.9	-3.3	-15.2
1189	NWE	1991	16	20	31	-11	-4	-15.1
1188	NYJ	1995	16	22	34.9	-12.9	-2	-15
1187	CHI	2000	16	18	33.7	-15.7	0.8	-14.9
1186	JAX	2011	16	21	35.8	-14.8	-0.1	-14.9
1185	KAN	1988	16	24	35	-11	-3.9	-14.9
1184	DEN	1971	14	19.4	31.7	-12.3	-2.5	-14.8
1183	OAK	2008	16	22	35.1	-13.1	-1.6	-14.7
1182	NYJ	1976	14	19.4	34.5	-15.1	0.7	-14.4
1181	CLE	2009	16	21	35.6	-14.6	0.3	-14.3
1180	KAN	1982	9	23.1	35	-11.9	-2.3	-14.2
1179	CLE	2005	16	19	33.6	-14.6	0.5	-14.1
1178	SFO	2007	16	23	34.6	-11.6	-2.4	-14
1177	SEA	1982	9	23.1	35	-11.9	-2.1	-14
1176	STL	2010	16	27	35.9	-8.9	-5	-14
1175	BUF	2007	16	20	34.6	-14.6	0.7	-13.8
1174	DEN	1982	9	24.9	35	-10.1	-3.7	-13.8
1173	ATL	1977	14	19.4	30.2	-10.8	-2.9	-13.7
1172	PIT	1998	16	21	34.6	-13.6	-0.1	-13.7
1171	ARI	1995	16	20	34.9	-14.9	1.3	-13.6
1170	CLE	2008	16	17	35.1	-18.1	4.5	-13.6
1169	TAM	2006	16	20	33.5	-13.5	-0.1	-13.6
1168	IND	1984	16	26	36.6	-10.6	-2.9	-13.5
1167	DAL	2002	16	21	36.1	-15.1	1.6	-13.5
1166	CLE	2011	16	20	35.8	-15.8	2.4	-13.4
1165	CIN	2008	16	17	35.1	-18.1	4.8	-13.3
1164	NWE	1990	16	18	34	-16	2.7	-13.3
1163	PHI	1976	14	21.7	34.5	-12.8	-0.4	-13.2
1162	BAL	1983	16	22	37.9	-15.9	2.8	-13.2
1161	CLE	1984	16	24	36.6	-12.6	-0.5	-13.1
1160	PHI	1984	16	25	36.6	-11.6	-1.5	-13.1
1159	IND	2011	16	22	35.8	-13.8	0.7	-13.1
1158	DAL	1989	16	21	34.6	-13.6	0.6	-13.1
1157	ARI	2005	16	23	33.6	-10.6	-2.3	-12.9
1156	DET	2004	16	26	35.9	-9.9	-2.9	-12.8
1155	BAL	1982	9	17.8	35	-17.2	4.5	-12.7
1154	ATL	1987	15	23.5	37	-13.6	0.8	-12.7
1153	NOR	1985	16	24	37.2	-13.2	0.5	-12.7
1152	CHI	1993	16	17	29.3	-12.3	-0.4	-12.7
1151	NOR	1997	16	22	33.4	-11.4	-1.3	-12.7
1150	CIN	2000	16	19	33.7	-14.7	2.1	-12.7
1149	KAN	2007	16	23	34.6	-11.6	-1.1	-12.6
1148	TAM	1983	16	27	37.9	-10.9	-1.7	-12.6
1147	PHI	1985	16	27	37.2	-10.2	-2.4	-12.5
1146	CHI	2005	16	22	33.6	-11.6	-0.9	-12.5
1145	DET	1979	16	25	36.6	-11.6	-0.8	-12.4
1144	ATL	1976	14	22.9	34.5	-11.7	-0.5	-12.2
1143	TAM	1996	16	20	33	-13	0.8	-12.2
1142	DET	2003	16	22	33.8	-11.8	-0.3	-12.1
1141	CAR	2000	16	26	33.7	-7.7	-4.2	-12
1140	STL	2007	16	24	34.6	-10.6	-1.4	-12
1139	BAL	1998	16	23	34.6	-11.6	-0.3	-11.9
1138	NYJ	2007	16	21	34.6	-13.6	1.7	-11.9
1137	CHI	1974	14	20.6	32.6	-12	0.2	-11.8
1136	SDG	1975	14	24	37.2	-13.2	1.4	-11.7
1135	GNB	1973	14	19.4	31.1	-11.7	0	-11.7
1134	CAR	2002	16	26	36.1	-10.1	-1.6	-11.7
1133	CAR	2001	16	21	32.3	-11.3	-0.4	-11.7
1132	NWE	1992	16	19	30.3	-11.3	-0.4	-11.7
1131	NOR	1970	14	17.1	31.6	-14.5	2.8	-11.7
1130	ARI	2000	16	22	33.7	-11.7	0.1	-11.7
1129	NYJ	2005	16	21	33.6	-12.6	1	-11.6
1128	CLE	1988	16	29	35	-6	-5.6	-11.6
1127	TAM	1995	16	24	34.9	-10.9	-0.7	-11.6
1126	JAX	2004	16	26	35.9	-9.9	-1.7	-11.6
1125	NYJ	1992	16	20	30.3	-10.3	-1.2	-11.5
1124	PHO	1991	16	16	31	-15	3.6	-11.4
1123	SDG	1999	16	22	33.2	-11.2	-0.2	-11.4
1122	DET	1987	15	26.7	37	-10.4	-1	-11.4

In the dominant offensive environment of 2011, five teams slipped well below the average: Indianapolis, Cleveland, Jacksonville, St. Louis and Kansas City. The worst three offenses were the Marc Bulger/Kyle Boller/Keith Null 1-15 Rams from 2009, the Andrew Walter-led Raiders, and the sophomore version of the ‘Yucs. It is amazing that the 2004 Bears ranked last in both points and yards despite facing one of the weakest slate of defenses that you’ll ever see.

What about the top defenses? I’m grading defenses by touchdowns allowed under average, but to be consistent with the above, a positive number is a good thing in both cases: a higher number means more touchdowns allowed under average and a higher number means a more difficult schedule (i.e., faced more good offenses):

RK	Tm	Year	G	DTD	LGAVG	TDundAVG	SOS	RATING
1	PIT	1976	14	16	34.5	18.5	1.5	20
2	MIN	1970	14	11.4	31.6	20.2	-0.4	19.9
3	MIN	1971	14	13.7	31.7	18	1.2	19.3
4	NYJ	2009	16	19	35.6	16.6	2.5	19.1
5	CHI	1986	16	16	35.3	19.3	-1.1	18.2
6	TAM	2002	16	18	36.1	18.1	-0.1	18
7	DEN	1977	14	18.3	30.2	11.9	5.1	17
8	CHI	1985	16	22	37.2	15.2	1.7	16.9
9	PIT	1975	14	19.4	37.2	17.8	-1.2	16.5
10	BAL	2004	16	23	35.9	12.9	3.5	16.3
11	JAX	2004	16	25	35.9	10.9	5.2	16.1
12	PIT	2010	16	20	35.9	15.9	0	16
13	PIT	2008	16	19	35.1	16.1	-0.2	15.9
14	GNB	2010	16	22	35.9	13.9	1.9	15.8
15	MIN	1973	14	14.9	31.1	16.3	-0.5	15.7
16	TAM	1999	16	19	33.2	14.2	1.4	15.6
17	RAM	1975	14	17.1	37.2	20	-4.8	15.2
18	NYG	1990	16	21	34	13	1.6	14.6
19	MIA	1998	16	23	34.6	11.6	3	14.6
20	NOR	1991	16	18	31	13	1.2	14.3
21	CHI	1984	16	24	36.6	12.6	1.6	14.2
22	CHI	2001	16	18	32.3	14.3	-0.1	14.2
23	DEN	1978	16	21	32.9	11.9	2.2	14.2
24	MIA	1975	14	26.3	37.2	10.9	3.3	14.2
25	PIT	1972	14	17.1	33.8	16.6	-2.7	14
26	TEN	2000	16	17	33.7	16.7	-3	13.8
27	NYG	1981	16	24	36.9	12.9	0.9	13.7
28	PHI	1980	16	24	37	13	0.7	13.7
29	BAL	2000	16	16	33.7	17.7	-4.1	13.6
30	MIN	2008	16	25	35.1	10.1	3.3	13.4
31	GNB	1996	16	19	33	14	-0.7	13.3
32	DET	1980	16	23	37	14	-0.8	13.3
33	MIA	1973	14	17.1	31.1	14	-0.7	13.3
34	CLE	1988	16	26	35	9	4	13
35	PHI	2001	16	19	32.3	13.3	-0.3	13
36	DEN	1979	16	27	36.6	9.6	3.3	12.9
37	SFO	1987	15	22.4	37	14.6	-1.7	12.9
38	PHI	1991	16	20	31	11	1.8	12.8
39	HOU	1980	16	24	37	13	-0.3	12.7
40	PIT	1990	16	22	34	12	0.7	12.7
41	DAL	1996	16	20	33	13	-0.3	12.7
42	PIT	1994	16	19	33	14	-1.3	12.6
43	TAM	1997	16	23	33.4	10.4	2.2	12.6
44	BAL	2006	16	21	33.5	12.5	0	12.5
45	NOR	1992	16	21	30.3	9.3	3.2	12.5
46	MIA	2000	16	22	33.7	11.7	0.7	12.5
47	KAN	1995	16	23	34.9	11.9	0.5	12.5
48	GNB	1972	14	24	33.8	9.8	2.7	12.5
49	PHI	1981	16	23	36.9	13.9	-1.4	12.4
50	BUF	1999	16	21	33.2	12.2	0.2	12.4
51	WAS	2000	16	21	33.7	12.7	-0.4	12.3
52	SFO	1985	16	21	37.2	16.2	-4	12.2
53	PHI	2007	16	26	34.6	8.6	3.6	12.1
54	CHI	2005	16	19	33.6	14.6	-2.5	12
55	TAM	2003	16	22	33.8	11.8	0.2	12
56	CHI	1988	16	23	35	12	0	12
57	BAL	1971	14	19.4	31.7	12.3	-0.3	12
58	CLE	1987	15	23.5	37	13.6	-1.7	11.9
59	WAS	1971	14	20.6	31.7	11.2	0.6	11.8
60	TAM	1981	16	26	36.9	10.9	0.9	11.7
61	SFO	1989	16	24	34.6	10.6	1.1	11.7
62	PIT	2004	16	22	35.9	13.9	-2.2	11.7
63	IND	1989	16	25	34.6	9.6	2	11.7
64	NWE	2006	16	21	33.5	12.5	-0.8	11.7
65	BAL	2008	16	21	35.1	14.1	-2.4	11.6
66	IND	2008	16	24	35.1	11.1	0.5	11.6
67	SFO	1995	16	24	34.9	10.9	0.6	11.5
68	RAI	1990	16	24	34	10	1.5	11.5
69	PIT	1996	16	24	33	9	2.5	11.5
70	NYG	1986	16	25	35.3	10.3	1.2	11.5
71	WAS	1974	14	22.9	32.6	9.7	1.7	11.4
72	ATL	1977	14	16	30.2	14.2	-2.8	11.4
73	PIT	1979	16	28	36.6	8.6	2.7	11.3
74	DEN	1984	16	26	36.6	10.6	0.7	11.3
75	CAR	2009	16	29	35.6	6.6	4.6	11.2
76	RAM	1973	14	17.1	31.1	14	-2.8	11.2
77	MIN	1988	16	22	35	13	-1.9	11.1
78	NWE	2004	16	27	35.9	8.9	2.2	11.1
79	OAK	1973	14	19.4	31.1	11.7	-0.6	11.1
80	MIA	1982	9	24.9	35	10.1	1	11.1
81	TEN	2008	16	24	35.1	11.1	0	11
82	NYJ	1985	16	27	37.2	10.2	0.8	11
83	DEN	1976	14	25.1	34.5	9.4	1.6	11
84	JAX	2006	16	26	33.5	7.5	3.3	10.8
85	PIT	1978	16	21	32.9	11.9	-1.1	10.8
86	MIA	1979	16	26	36.6	10.6	0.1	10.7
87	RAI	1985	16	29	37.2	8.2	2.4	10.6
88	SFO	1981	16	26	36.9	10.9	-0.3	10.6
89	NWE	2003	16	21	33.8	12.8	-2.3	10.5
90	BUF	1981	16	28	36.9	8.9	1.6	10.5
91	WAS	1973	14	22.9	31.1	8.3	2.3	10.5
92	DAL	1970	14	22.9	31.6	8.8	1.7	10.5
93	SFO	2011	16	23	35.8	12.8	-2.4	10.4
94	MIA	1972	14	20.6	33.8	13.2	-2.8	10.4
95	CLE	1984	16	25	36.6	11.6	-1.5	10.1
96	BUF	1980	16	29	37	8	2.1	10.1
97	KAN	1979	16	30	36.6	6.6	3.5	10.1
98	DAL	2009	16	26	35.6	9.6	0.5	10.1
99	CHI	2011	16	32	35.8	3.8	6.3	10.1
100	DAL	1973	14	22.9	31.1	8.3	1.9	10.1

In the case of the Steelers and the Bears, it’s not their championship defenses that rank first. In Pittsburgh, the ’76 Steelers had one of the most dominant nine-game stretches ever, and allowed only one touchdown per game despite facing a difficult schedule. The ’86 Bears not only allowed fewer points than the ’85 version, but they had a significant edge in touchdowns allowed, although much of that is explained by strength of schedule.

Comparing two of the best modern defenses reveals some interesting results. The 2000 Ravens had a really easy schedule, playing some particularly anemic offenses. The Ravens rank 8th in offensive touchdowns allowed if you remove SOS and the 2002 Bucs rank 5th; once you adjust for SOS, Tampa Bay drops only one spot while Baltimore falls all the way down to 29.

The easiest SOS any defense faced since 1970? That would be the slate of opponents the 1979 Buccaneers played; the average offense was 6.6 touchdowns below average, which helped Tampa Bay post some unbelievable defensive numbers that season. The 1998 Arizona Cardinals, often mentioned as the worst playoff team ever, faced the second worst group of offenses (-6.5).

What about the worst 100 defenses?

RK	Tm	Year	G	DTD	LGAVG	TDundAVG	SOS	RATING
1221	BAL	1981	16	67	36.9	-30.1	1.7	-28.4
1220	NWE	1972	14	58.3	33.8	-24.5	0.7	-23.8
1219	TAM	1986	16	54	35.3	-18.8	-4.2	-23
1218	SEA	1976	14	53.7	34.5	-19.2	-3.5	-22.7
1217	NOR	1980	16	59	37	-22	0.7	-21.3
1216	ATL	1985	16	56	37.2	-18.8	-1.9	-20.7
1215	NYJ	1996	16	52	33	-19	-1	-20
1214	KAN	1976	14	56	34.5	-21.5	1.4	-20
1213	HOU	1973	14	51.4	31.1	-20.3	0.7	-19.6
1212	DET	2008	16	56	35.1	-20.9	1.4	-19.5
1211	SDG	1985	16	53	37.2	-15.8	-3.2	-19
1210	RAM	1982	9	51.6	35	-16.6	-2.4	-19
1209	DEN	2010	16	52	35.9	-16.1	-1.8	-17.9
1208	PHI	1973	14	50.3	31.1	-19.2	1.3	-17.9
1207	SDG	1971	14	45.7	31.7	-14	-3.7	-17.7
1206	CIN	1999	16	50	33.2	-16.8	-0.8	-17.6
1205	STL	2000	16	50	33.7	-16.3	-1.1	-17.3
1204	CHI	1975	14	53.7	37.2	-16.5	-0.8	-17.3
1203	ARI	2008	16	49	35.1	-13.9	-3	-17
1202	DET	2009	16	53	35.6	-17.4	0.6	-16.8
1201	CLE	1990	16	53	34	-19	2.4	-16.6
1200	IND	2001	16	50	32.3	-17.7	1.1	-16.6
1199	PHO	1990	16	49	34	-15	-1.5	-16.5
1198	SFO	2004	16	49	35.9	-13.1	-3.3	-16.4
1197	SDG	1973	14	46.9	31.1	-15.7	-0.7	-16.4
1196	MIN	1984	16	55	36.6	-18.4	2.1	-16.2
1195	STL	2005	16	48	33.6	-14.4	-1.7	-16.1
1194	DET	2007	16	51	34.6	-16.4	0.4	-16
1193	NOR	1977	14	41.1	30.2	-10.9	-5	-15.9
1192	NOR	1999	16	49	33.2	-15.8	0	-15.8
1191	NYG	2009	16	52	35.6	-16.4	0.8	-15.6
1190	TAM	2011	16	56	35.8	-20.2	4.6	-15.6
1189	ATL	2003	16	49	33.8	-15.2	-0.3	-15.6
1188	RAM	1990	16	47	34	-13	-2.3	-15.3
1187	IND	1991	16	45	31	-14	-1.2	-15.2
1186	BUF	1971	14	46.9	31.7	-15.1	0.3	-14.8
1185	NYG	1980	16	53	37	-16	1.3	-14.7
1184	NWE	1990	16	50	34	-16	1.3	-14.7
1183	PHI	1972	14	48	33.8	-14.2	-0.5	-14.7
1182	BOS	1970	14	44.6	31.6	-12.9	-1.8	-14.7
1181	ARI	2000	16	48	33.7	-14.3	-0.4	-14.6
1180	HOU	1970	14	46.9	31.6	-15.2	0.6	-14.6
1179	BUF	1972	14	51.4	33.8	-17.7	3.1	-14.5
1178	SEA	1977	14	45.7	30.2	-15.5	1	-14.5
1177	HOU	1982	9	49.8	35	-14.8	0.3	-14.5
1176	SDG	1983	16	54	37.9	-16.1	1.7	-14.3
1175	MIN	2002	16	48	36.1	-11.9	-1.9	-13.9
1174	SFO	2000	16	47	33.7	-13.3	-0.5	-13.8
1173	WAS	1994	16	46	33	-13	-0.7	-13.8
1172	HOU	1984	16	50	36.6	-13.4	-0.3	-13.7
1171	HOU	1989	16	48	34.6	-13.4	-0.3	-13.7
1170	CIN	1985	16	49	37.2	-11.8	-1.9	-13.7
1169	CIN	1991	16	46	31	-15	1.4	-13.5
1168	HOU	1983	16	49	37.9	-11.1	-2.4	-13.5
1167	ATL	1987	15	53.3	37	-16.3	2.8	-13.5
1166	NYJ	1975	14	58.3	37.2	-21.1	7.6	-13.5
1165	CLE	1999	16	46	33.2	-12.8	-0.6	-13.4
1164	GNB	1983	16	48	37.9	-10.1	-3.2	-13.2
1163	SEA	2010	16	44	35.9	-8.1	-5.1	-13.2
1162	SFO	1979	16	49	36.6	-12.4	-0.7	-13.1
1161	STL	1981	16	49	36.9	-12.1	-1	-13.1
1160	MIN	2004	16	45	35.9	-9.1	-3.9	-13
1159	SFO	2005	16	47	33.6	-13.4	0.4	-13
1158	GNB	2004	16	45	35.9	-9.1	-3.8	-13
1157	TEN	2001	16	44	32.3	-11.7	-1.2	-12.9
1156	BUF	1984	16	51	36.6	-14.4	1.5	-12.9
1155	SDG	2003	16	48	33.8	-14.2	1.4	-12.8
1154	DAL	2004	16	45	35.9	-9.1	-3.6	-12.7
1153	MIA	1986	16	45	35.3	-9.8	-2.9	-12.7
1152	CIN	1997	16	45	33.4	-11.6	-1	-12.6
1151	WAS	2003	16	43	33.8	-9.2	-3.4	-12.6
1150	STL	1987	15	49.1	37	-12	-0.5	-12.6
1149	CLE	1975	14	52.6	37.2	-15.4	2.8	-12.6
1148	SDG	1984	16	50	36.6	-13.4	0.8	-12.5
1147	ATL	1996	16	44	33	-11	-1.5	-12.5
1146	STL	2006	16	42	33.5	-8.5	-4	-12.5
1145	NOR	1979	16	46	36.6	-9.4	-3	-12.4
1144	IND	1993	16	42	29.3	-12.7	0.4	-12.3
1143	BUF	2011	16	49	35.8	-13.2	1	-12.3
1142	CIN	1992	16	39	30.3	-8.7	-3.6	-12.2
1141	SDG	1981	16	47	36.9	-10.1	-2	-12.2
1140	NYJ	1989	16	47	34.6	-12.4	0.2	-12.2
1139	BAL	1996	16	45	33	-12	-0.1	-12.1
1138	KAN	1975	14	48	37.2	-10.8	-1.1	-11.9
1137	ATL	1992	16	44	30.3	-13.7	1.8	-11.8
1136	BAL	1978	16	50	32.9	-17.1	5.3	-11.8
1135	TEN	2005	16	45	33.6	-11.4	-0.4	-11.8
1134	NYJ	1986	16	47	35.3	-11.8	0	-11.7
1133	KAN	2004	16	50	35.9	-14.1	2.7	-11.5
1132	TAM	1984	16	47	36.6	-10.4	-1.1	-11.5
1131	PHO	1988	16	49	35	-14	2.5	-11.5
1130	CIN	1998	16	46	34.6	-11.4	0	-11.5
1129	GNB	1986	16	47	35.3	-11.8	0.3	-11.5
1128	NOR	1976	14	45.7	34.5	-11.2	-0.2	-11.4
1127	SFO	1980	16	49	37	-12	0.7	-11.3
1126	DEN	2008	16	46	35.1	-10.9	-0.3	-11.3
1125	HOU	1985	16	50	37.2	-12.8	1.6	-11.3
1124	WAS	1998	16	45	34.6	-10.4	-0.8	-11.2
1123	HOU	2005	16	45	33.6	-11.4	0.2	-11.2
1122	BUF	1975	14	52.6	37.2	-15.4	4.2	-11.2

The 1981 Colts allowed an incredible 67 offensive touchdowns, putting them a distant last in the group. Also in the bottom 10: the 2011 Bucs that basically quit for the last 10 games and the 0-16 2008 Detroit Lions.

But I don’t just want to look at lists today. Which brings us to…

Part II – Analysis of OTDs and DTDs and SOS

In general, the elite offenses are farther away from average than the elite defenses. In other words, the best offenses are better at offenses than the best defenses are at defense. ^[1]Since 1970, 61 teams have averaged one more offensive touchdown per game than average and 33 teams have averaged at least one fewer offensive touchdown per game than average. On the other side, only … Continue reading The same is true when you look at strength of schedule. For offenses — because defenses are more tightly packed — the spread on the strength of schedule numbers is smaller. ^[2]For example, only 23 teams faced defenses that allowed 0.25 (or fewer) fewer touchdowns per game than average, while 39 teams faced offenses that were, on average, 0.25 or more touchdowns per game … Continue reading Both of those factors combine to make offensive rankings less susceptible to SOS adjustments than defensive rankings.

I looked at the top and bottom 100 offenses in non-SOS adjusted offensive touchdowns over average and noted how they performed the next year. The top 100 offenses, on average, were 17.4 touchdowns over average and had an SOS of -0.6; the next season, those offenses averaged 9.3 touchdowns over average. The bottom 100 offenses were 14.2 touchdowns below average, faced a schedule that was +0.4 touchdowns harder than average, and were 5.3 touchdowns below average the next season.

The two key takeaways: strength of schedule had a pretty minimal effect for those extreme teams and there was significant but not overwhelming regression.

The top 100 defenses (again, not adjusting for SOS) allowed 12.8 fewer touchdowns than average and had a slightly easier (-0.5) schedule than average. But the next season, they were only 4.5 touchdowns below average. The worst 100 defenses were 14.9 touchdowns worse than average and had a slightly harder (+0.8) schedule than average. In Year N+1, they were only 4.8 touchdowns below average.

So the best offenses (+17.4) were better than the best defenses (+12.8) and regressed by significantly less than next season (+9.3 vs. +4.5). This is one of the reasons that having a great offense is better for the long-term health of a franchise than having a great defense. The correlation coefficient between Year N TDabAVG and Year N+1 TDabAVG was 0.47, while the CC between those variables on the defensive side of the ball was 0.35. The correlation coefficient between (unadjusted) Year N TDabAVG and Year N SOS was -0.10 for the offense (the weaker the SOS, the better the production) and -0.17 on defense. While not significant, this does indicate that strength of schedule has a larger impact on defensive numbers than offensive production.