NFL Defense Analysis: Steel Curtain Most Dominant

All the talk about the Legion of Boom got me wondering about how the Seahawks' vaunted D compares with other Ds in other eras. The stats are all from the NFL official website. The most dominant defenses have been; Rams (73-77), Steelers (73-77), Da Bears (83-87), Bucs (2001-05), Ravens (1999-2002) and Seahawks. Taking 5 year averages is a bit arbitrary but we can look at individual years within this range. The Purple People Eaters of the 70s don't make the list because within the span of the Vikes' fruitless SB appearance they only led a defensive category in one year. All of the selected tenacious Ds have at least two. I think that the most meaningful stats are both the absolute and relative ppgs (points per game) but ypg, sacks, interceptions and fumbles are all relevant. It is first worth noting that both ppgs and ypgs have increased over time. Avg ypg in 1970 were 270; in 2016 345 and ppg from 19 to 22, with a fair amount of yearly variation for each. The 75 Rams hold the season record (14 games) for lowest ppg and for lowest ppg relative to the league average. For yardage it's the Steelers by a huge difference. The Rams also have the lowest five year ppg avg. Incredibly, though, the Rams did not win a SB in its D heyday whereas the Steel Curtain racked up 2 wins. As much as I was hoping that Da Bears would come out on top, the Steelers seem to edge out the Rams for the crown. However, Da Bears do clearly lead in Sacks, which made them so much fun to watch. As far as I can see, no official stats are kept on yards lost due to sacks. The Seahawks D really does not stack up against the others. The Legion of Boom may be, arguably, the best secondary but the total D is not that impressive in historical context.

RAMS
1973	12.71	211	45	20	1	3	68%	77%	21	0
1974	12.9	243	44	24	2	0	74%	88%	29	0
1975	9.6	237.3	43	22	2	1	48%	80%	26	1
1976	13.6	261.1	45	32	3	1	71%	86%	29	0
1977	10.4	255.4	36	25	1	0	61%	89%	32	0
	11.85	241.55	42.6	24.6	1.8	1	65%	83%	26.25	0.25

STEELERS
1973	15	210	33	37	3	1	80%	76%	36	1
1974	13.5	189	52	25	2	1	77%	68%	33	1
1975	11.6	162	43	27	2	0	58%	55%	34	1
1976	9.9	138	41	22	0	1	52%	46%	40	0
1977	17.4	243	32	31	0	0	101%	85%	28	0
	12.50	174.75	40.2	28.4	1.4	0.6	72%	66%	34.33333333	1

BUCs	PPG	YPG	SACKS	INT	TDs	Safety	PPG %avg	YPG%avg	Fumbles	TDs
2001	17.5	280	42	28	0	0	90%	90%	20	0
2002	12.25	252.8	43	31	4	1	58%	79%	24	1
2003	16.5	264	36	20	3	1	81%	85%	23	0
2004	19	304	45	16	1	0	91%	95%	32	0
2005	17.1	274	36	17	3	1	86%	89%	16	1
	16.47	274.96	40.4	22.4	2.2	0.6	80%	87%	24.75	0.25

RAVENS	PPG	YPG	SACKS	INT	TDs	Safety	PPG %avg	YPG%avg	Fumbles	TDs
1999	17.3	277	49	21	4	1	85%	88%	24	0
2000	10.3	165	35	23	0	1	51%	53%	26	0
2001	16.6	265	45	16	1	0	85%	85%	31	1
2002	22.1	354	33	25	2	0	105%	110%	34	1
2003	17.6	281	47	24	0	0	86%	90%	37	0
	16.78	268.40	41.8	21.8	1.4	0.4	81%	84%	30.4	0.4

SEAHAWKS	PPG	YPG	SACKS	INT	TDs	Safety	PPG %avg	YPG%avg	Fumbles	TDs
2012	15.3	306	36	18	2	0	68%	90%	16	1
2013	14.4	274	42	28	3	2	62%	79%	29	1
2014	15.9	267	37	13	1	1	72%	78%	27	0
2015	17.3	292	37	14	0	0	78%	85%	17	3
2016	18.2	319	42	11	0	1	82%	93%	22	1
	16.22	291.6	38.8	18.25	1.2	0.75	70%	83%	22.25	1.25

BEARS	PPG	YPG	SACKS	INT	TDs	Safety	PPG %avg	YPG%avg	Fumbles
1983	18.8	321	51	21	2	0	86%	96%	25	1
1984	15.5	241	72	21	1	1	73%	73%	31	0
1985	12.4	258	64	34	4	3	58%	79%	24	1	SB
1986	11.7	258	62	31	1	2	57%	80%	36	1
1987	18.8	281	70	13	0	2	87%	86%	33	0
		15.44	271.8	63.8	24	1.6	1.6	72%	83%	29.8	0.6