The experts think the Denver Broncos do not have enough offense to cope with the Oakland Raiders and thus cannot count on a fourth-quarter flurry if they fall behind, despite their success against Pittsburgh in the playoff opener last week.

The teams meet for the AFC championship Sunday (WRC-TV-4 at 2 p.m. EST).

The fact is that the Broncos outscored their opponents in the fourth quarter during the regular season, 74-17, including two games against the Raiders.

The Raiders outscored their opponents by only 58-57 in the last period.

The Denver people insist their Broncos have no built-in advantage playing in the rarefied atmosphere of the Mile High City, noting that the Broncos won as many games on the road as at home. They lost at home against Oakland and beat the Raiders on the road.

They recall the the St. Louis Cardinals came out to the mountains of neighboring Wyoming to become acclinated, but still lost, 7-0, to the Broncos.

Visitors here are supposed to run out of the energy in the final quarter, whether the thin air is actually enervating or because the opposition thinks it is. But the Raiders are favored to rise above any such a handicap for the basis reason they have scored far more points than the Broncos, 351 to 274.

Even with that, there is a balancing factor: The fans may like exciting teams, but, with few exceptions, coaches know defense wins most of the time and the Broncos have given up only 148 points to the Raiders' 230.

Denver's problem is pass defense. The Broncos ranked 12th in that department and will be going against a team that passes well.

The Broncos are thought of as a ball-control club but they ranked only seventh in rushing. Actually, the Broncos are more of a "minimum-mistake" team, with a total offense that ranked 12th and a passing game that was last in the AFC.

Denver did nicely in total defense, finishing fourth. The Broncos were first against the rush but that accomplishment will be tested by the Raiders' running game, which finished No. 1 in the conference.

Fullback Mark van Eeghen led the AFC in rushing with 1,273 yards and combined with Clarence Davis, most valuable player in the Raiders' Super Bowl triumph over Minnesota, for 2,060 yards.

There were no Broncos among the leaders in rushing or pass catching.

Statistically, Denver's Craig Morton finished second to Bob Griese of Miami in passing, with Oakland's Ken Stabler fourth behind Baltimore's Bert Jones. But what you see on television is Stabler dazzling the opposition with his zingers to tight end Dave Casper, and wide receiver Fred Biletnikoff.

Morton is prudent in the use of the pass although he had more than adequate receivers in tight end Riley Odoms and Haven Moses and Jack Dolbin.

Denver coach Red Miller plays for field position and takes no chances on the Broncos' side of the 50-yard line, but Oakland punter Ray Guy is the marvel of his time in taking away field position from rivals and providing opportunities for Stabler.

As the Raiders took care to point out in a publicity release, Morton is no innocent abroad in big games.

Besides his victory over the Steelers last Saturday, Morton played in five NFC playoff games, an NFC title game and a Super Bowl, losing to Baltimore, 16-13, on a fumble by Duane Thomas at the Colts' two-yard line and or on a still-disputed deflected pass by Earl Morrall that went to tight end John Mackey for a touchdown.

The Broncos have seven other players who have been in playoff games - Bernard Jackson (with Cincinnati), Ire (Buffalo), Andy Maure and Randy Poltl (both with Minnesota), Jim Jensen (Dallas) and Jim Turner (New York Jets).