What made the Pittsburgh Steelers of the late 1970s even better than the Steelers of the mid 1970s, was the rule changes on offense in the NFL in 1978. That improved the blocking and opened up the running and passing games on offense. And opened up the passing game also with the illegal contact rule that allowed for WR’s to be able to get off of the line of scrimmage and run their patterns.
Before the rule changes the Steelers were a power run ball control offense. That would rely on their Steel Curtain defense to set up great field position for them and get them takeaways. And when defenses tried to take their running game away by stacking the line of scrimmage, the Steelers also had deep threats in the passing game with WR’s John Stallworth and Lynn Swann and QB Terry Bradshaw.
Bradshaw being one of the best deep passing QB’s of all-time, but with the rule changes on offense the Steelers had to find more ways to score and to be able to score more points. As we saw in Super Bowl 13 against the Dallas Cowboys and Super 14 against the Los Angeles Rams. The 1978 rule changes on offense in the NFL opened up the Steelers offense and made them a vertical passing and power running team, to go with their great defense.