The thing that probably concerns National Football League coaches most during the playoffs is the problem of turnovers - mistakes that not only kill one of their own team's drives but give the ball back to the opposition.
The Dallas Cowboys, for example, in their 24-17 loss to the Los Angeles Rams Monday, turned the ball over four times in the second half via a fumble and three interceptions. That proved to be a luxury that not even the Cowboys could afford.
In the weekend's other wild card game, the Denver Broncos committed a pair of demoralizing second quarter turnovers in their 31-7 loss to Seattle. A Steve DeBerg pass was picked off near the Seahawk goal line and returned 45 yards to snuff out one scoring opportunity, and a fumble at the Seattle six-yard line wiped out another.
Ordinarily Seattle's two-tight end offense is fairly predictable, but when Seahawk coach Chuck Knox had his team throwing on first downs to start the second half, the Broncos were unable to adjust to it. As a result, the Seattle's 10-7 halftime lead mushroomed into a rout.
The Seahawks now face the unenviable task of meeting the Dolphins in Miami next Saturday, while on Sunday Pittsburgh takes on the Los Angeles Raiders in the other AFC contest.
In NFC games, it's Detroit at San Francisco on Saturday and the Rams at Washington on Sunday.
What the Rams can look forward to next against the defending Super Bowl champion Redskins, who embarrassed them 40-20 during the regular season, is a team that makes very few mistakes. Washington also has the best short-yardage runner in the business in 230-lb. John Riggins.
If sports-car backs like Tony Dorsett are judged on the way they get outside, break the corner, and turn upfield, then those whose job it is to go inside ought to be judged on how well they barrel into the line. Riggins does it as though he's taken lessons from a Clydesdale horse.
Although Joe Gibbs is the Redskins' head coach, the man who decides how often Riggins comes off the field for a rest is John himself. ''If Riggins wants out, he tells me,'' Gibbs explained. ''And it's better that way because nobody knows John better than he knows himself.''
Gregg returns to Green Bay
When the late Vince Lombardi of the Green Bay Packers wrote his book ''Run to Daylight,'' he made the flat statement that ''Forrest Gregg is the finest lineman I have ever coached.'' Last week Gregg, a member of pro football's Hall of Fame since 1977, was given a five-year contract to succeed Bart Starr as head coach of the Packers, who made the playoffs only once during Starr's nine years in Green Bay.
Gregg, who had previously coached the NFL Cleveland Browns plus Toronto in the Canadian Football League, took over the Cincinnati Bengals in 1980. What Forrest inherited was a team coming off back-to-back 4-12 seasons that suggested a lot of personnel changes and a long rebuilding period. Instead Gregg turned things around quickly by getting the Bengals into the 1982 Super Bowl against San Francisco. He still had one year left on his Cincinnati contract when the Packers asked for permission to talk with him.
''Ordinarily I wouldn't release a coach of Gregg's caliber,'' said Cincinnati General Manager Paul Brown. ''But because of his earlier relationships with the Packers, I felt his decision to stay or go should be his own. To us Gregg was special because how many coaches ever take you to the Super Bowl?'' NFL tidbits
* Court records have revealed that running back Billy Sims of the Detroit Lions has signed three pro contracts and not just two as previously reported. Two of those agreements are with the USFL's Houston Gamblers and one with the Lions. Both teams plan legal battles to obtain his services.
* Owner Bob Irsay of the Baltimore Colts told the Baltimore News-American that he has turned down offers from New York City officials of a rent-free, 99 -year lease if he will move the Colts to Shea Stadium. New York, of course, is losing its Jets to the New Jersey Meadowlands complex next season.