When the Pittsburgh Steelers are good, they are very good. But when they're bad, they're indistinguishable from Cincinnati, St. Louis or Baltimore.

Because they did not ship well this season and lost games at Philadelphia, Cincinnati, San Diego, and Houston, there have been suggestions that the Steelers are not good on the road.

Pittsbughers point out the neither was Napoleon, particularly when it was snowing. The Steelers also won four games on the road this season, after winning their third Super Bowl as a touring attraction.

The Steelers struggled to beat the Cardinals, a 5-11 team by three points, and the Colts, another 5-11 team, by four.

Dallas was overpowered, 14-3; New England by three points, and Cleveland by three as the Browns scored 30 points on the Pittsburgh defense.

That was an improvement over their earlier meeting when the Browns managed 35 points to the Steelers' 51.

Before there is a groundswell to retire the Steelers' jerseys en masse, it must be noted that they were not so overwhelming that they could spot nine turnovers to a Cincinnati team that had the worst defense in the American Football Conference and the next-to-worst offense.

The Bengals decisioned them by 24 points in Cincinnati. Another measure of the Steelers' limited superiority came in San Diego, where they could not overcome four interceptions and were beaten by 28 points.

The losses in Philadelphia and Houston were respectable, each by three points.

The Steelers avenged themselves against the deteriorating Bengals, 37- 17, and rolled up scores of 28-0 against Buffalo, 30-3 against Kansas City, 38-7 against both Washington and Houston, and 42-7 against Denver.

Pittsburgh, a defector from the old National Football League format, won three of four from NFC teams -- Dallas, Washington and St. Louis -- losing to Philadelphia.

The Steelers are the best in the current phase of "parity" in the NFL and they may be on the verge of winning twice as many Super Bowls as Vince Lombardi's Geen Bay Packers and Don Shula's Miami Dolphins. Yet Pittsburgh might have had a better team last year.

It is a tribute to Coach Chuck Noll, who also does the drafting, that the Steelers have risen above injuries which would have undermined lesser teams.

The absence of Jack Ham is the big difference between this year's team and last year's. He will not play in the Super Bowl against Los Angeles because of a dislocated foot. Neither will free safety Mike Wagner, because he had calcium deposits removed from a hip.

Outside linebacker Ham was selected on just about every All-NFL team in 1978 and for the postseason Pro Bowl for the sixth straight time.

He rarely was trapped into serious error, inhibited opponents from running their right-handed ground games his way and was fast enough to cover backs evolving as pass receivers.

Wagner, an eight-season veteran, was the "quarterback" of the secondary. Fortunately, cornerback J. T. Thomas recovered from a blood disorder that sidelined him in 1978, and successfully made the switch to Wagner's free safety position.

Dennis Winston, in his third season, has filled in for Ham. Winston is faster than Ham but is still learning pass defense.

Early this season, defensive ends L. C. Greenwood and Dwight White and defensive tackle Steve Furness were injured, and end Tom Beasley and tackle Gary Dunn got valuable playing experience.

Three regular offensive linemen, Jon Kolb, Sam Davis and Gerry Mullins, have been in and out of the lineup with injuries, and missed the previous two playoff games. But again it served to develop youngsters such as Ted Petersen and Steve Courson.

Mullins is missed most, because his trap-blocking is so integral to the Steelers' running style, and he can play tight end.

Wide receiver Lynn Swann collided with a goal post in training camp and injured a roe. When he returned to action he pulled a hamstring and aggravated it in the playoff against Miami.

Running back Sidney Thornton missed six games with an injury before returning against Miami, and was injured again, but Rocky Bleier had recovered from chronic injuries before the playoff game against Houston.

Injuries are said to have limited the Los Angeles Rams to a 9-7 record, posing the question: How close would the Steelers, 12-4 in the regular season, have come to Don Shula's 17-0 record of 1972 if they were as impervious to bodily harm as Superman?