It is what it is said:
The best defense of all-time was the 1976 Pittsburgh Steelers. Despite playing four offensive juggernauts in Oakland, Minnesota, Cincinnati (twice) and New England (all top 10 offenses in '76)...the Pittsburgh Steeler Defense gave up just 138 points in 14 regular season games. Pittsburgh did this despite playing 5 of their 14 regular season games against top 10 scoring offenses.
The Pittsburgh offense was banged up most of the ('76) year with Terry Bradshaw, Lynn Swann and JC (John) Stallworth all being injured at various times during the season...and of course the huge loss of both Franco Harris and Rocky Bleier for the AFC Championship game. Rookie Mike Kruzcek took over for the injured Bradshaw at quarterback. Kruzcek never even threw for a single touchdown during his time as the starting QB, and despite this, Pittsburgh went 6-0 with him.
The Steeler defense led their club to a 9-0 finish, after starting the year just 1-4 (with losses to Oak, Minn, NE and Clev). Over the last 9 games of the regular season the Steeler Defense gave up just 28 points, for an average of just 3 points per game during this stretch. Including 5 shutouts by the Pittsburgh D!
That year the Pittsburgh Defense was lead by Pro Bowlers LB Jack Lambert, LB Jack Ham, DT "Mean" Joe Greene, DE LC Greenwood, DB Mike Wagner, DB Glenn Edwards, DB Mel Blount, DB JT Thomas. That was 8 of the 11 defensive starters for Pittsburgh who made the Pro Bowl that year. Leaving just LB Andy Russell, DE Dwight "Mad Dog" White and DT Ernie Holmes as the lone remaining starters who did not make the Pro Bowl. Also defensively DB Donnie Shell and DL Steve Furness were other well known contributers. Steeler HC Chuck Noll often said Ernie Holmes was his best D-lineman during this time period, which says both alot about the depth and talent on that club. Best I have ever seen...
The Steelers defense was the most dominating over a stretch I have ever seen also. Four Super Bowls in six years is about as good as it gets. They also had the best draft class ever:
1974
1 1 21 21 Lynn Swann WR USC
2 2 20 46 Jack Lambert LB Kent State
3 4 4 82 John Stallworth WR Alabama A&M
4 4 22 100 Jimmy Allen DB UCLA
5 5 21 125 Mike Webster C Wisconsin
6 6 19 149 James Wolf DE Prairie View A&M
7 6 20 150 Rick Druschel G North Carolina State
8 7 9 165 Allen Sitterle T North Carolina State
9 7 23 179 Scott Garske TE Eastern Washington
10 8 22 204 Mark Gefert LB Purdue
11 9 15 223 Tom Reamon RB Missouri
12 9 21 229 Charlie Davis T Texas Christian
13 10 9 243 Jim Kregel G Ohio State
14 10 20 254 Dave Atkinson DB Brigham Young
15 11 23 283 **** Morton RB Arkansas
16 12 22 308 Hugh Lickiss LB Simpson
17 13 21 333 Frank Kolch QB Eastern Michigan
18 14 20 358 Bruce Henley DB Rice
19 15 23 387 Larry Hunt DT Iowa State
20 16 22 412 Octavus Morgan LB Illinois
21 17 21 437 Larry Moore DE Angelo State