There was a time when Super Bowls were like film credits. They arrived at the end, briefly celebrated talented people, and signaled that the interesting stuff was over.

The modern Super Bowl is the epic it was always advertised to be. The event marked by the silly pomposity of Roman numerals has evolved into a sleek modern entertainment vehicle, packed with plot twists, story lines, celebrities and a zillion commercials.

In the olden days, back when "press conferences'' consisted of a few sportswriters sitting around a pool interviewing a shirtless Joe Namath, the matchups were often more intriguing than the games.

In the first 37 Super Bowls, the average margin of victory was 16.2 points, and in 20 of those games, the final margin was 15 points or more.

In the past 15 Super Bowls, the average margin of victory is 8.7 points, and there has been only one game decided by more than 15 points — the Seahawks' 43-8 victory over Denver in Super Bowl XLVIII.

The Patriots and Rams, who will meet in Super Bowl LIII on Sunday in Atlanta, embody this trend.

The Pats were patsies in their first two Super Bowl appearances, losing 46-10 to the Bears in 1986 and 35-21 to the Packers in 1997.

In their eight Super Bowl appearances since the arrival of Bill Belichick and Tom Brady, the Patriots are 5-3. They have outscored their opponents in those eight Super Bowls by a total of four points. In those eight games, only two have been decided by more than four points — when they scored an overtime touchdown to beat Atlanta in 2017, and when Brady fumbled on their final drive at U.S. Bank Stadium last year to seal the Eagles' eight-point victory.

The old version of the Los Angeles Rams made it to the Super Bowl once, losing to the Steelers 31-19 in 1980. While based in St. Louis, they played two thrillers, beating the Tennessee Titans by seven points and about a foot in 2000 and losing to the Patriots by three in 2002.

That game ushered in the Patriots dynasty. Belichick found a way to slow The Greatest Show On Turf, Brady won his first Super Bowl with a last-minute drive leading to a field goal.

Belichick and Brady may be the primary variables in the increase in close Super Bowls.

Many of the blowouts in the first 37 Super Bowls were the result of a dynasty flexing its muscles. When the Lombardi Packers, Landry or Johnson Cowboys or Walsh 49ers could keep all of their best players together, they could swamp a lesser opponent.

The Packers won the first two Super Bowls by 25 and 19 points. The average margin in the Cowboys' five Super Bowl victories was 20 points. The 49ers won Super Bowls by 22, 23 and 45 points.

In the free-agency era, maintaining dominance became trickier, and gameday coaching has become perhaps even more important. Perhaps that's why three of the past six Super Bowls have been decided in overtime or in the last seconds of regulation.

As a defensive coordinator, Belichick masterminded the Giants' 20-19 upset of the Buffalo Bills in 1991. The Giants had little offensive talent and the Bills had scored 51 points in the AFC Championship Game, but Belichick shackled the Bills' Hall of Famers in a game that would foreshadow his head coaching career.

Next Sunday in Atlanta, Belichick will try to do it again — try to suppress an impressive and innovative offense. His first Super Bowl title resulted from outthinking Rams offensive mastermind Mike Martz. This time, he'll square off with Sean McVay, the 33-year-old wunderkind.

The Rams have more obvious offensive talent. The Patriots have the better pedigree and the legendary coach. If you expect a blowout, you haven't been paying much attention to the Patriots dynasty or the modern Super Bowl.

Jim Souhan's podcast can be heard at TalkNorth.com. Twitter: @SouhanStrib E-mail: jsouhan@startribune.com