Offering an answer to a long-running sports-bar argument, statistics suggest that NFL preseason games have been truly meaningless, injuries aside, since 1994.

In 1978, the NFL added four "preseason" games that have no bearing on each team's eventual win-loss record ahead of the 16 regular-season games. Preseason games are widely seen as a chance for coaches to practice plays, scrubs to make the team and veterans to risk injuries. Preseason kicked off this year with the Arizona Cardinals playing the New Orleans Saints on Aug. 5.

Even NFL commissioner Roger Goodell has complained that the games are not "high-quality" affairs, notes a study in the current Journal of Sports Economics by economists Nancy Ammon Jianakoplos and Martin Shields of Colorado State University, raising questions about whether the games offer fans any insights into their team's Super Bowl chances.

"Does team performance in the NFL preseason predict team performance in the regular season," ask the researchers in the study. Noting that players don't get paid regular season game money during the preseason, "(a)n alternative approach views preseason games as an additional source of revenue for owners," say the authors.

Some studies dating back to 1994 have suggested that NFL preseason wins do offer hints to regular-season success, the study authors note, adding that statistics suggest a small correlation exists between preseason and regular season victories from 2002 to 2010. And what about the third preseason game, where veterans often play the longest, sometimes seen as a key dress rehearsal?

Taking a deeper look, the economists examined preseason success from 1970 to 1991 and compared it to 2002 to 2010 games.

The results offer one more reason to keep watching baseball in August, report the authors:

"Our main finding is that, although we confirm the significance of preseason winning as a predictor of regular season winning previously found in the 1970-1991 period, we are unable to find any statistical evidence that preseason winning percentage or winning the third game of the preseason provides any preview of NFL team performance in the regular season in the most recent 2002-2010 seasons."

So, what is going on? The team extended its analysis to bridge seasons from 1970 to 2010 and account for schedule strength. They find that, "preseason NFL performance lost its impact beginning with the 1994 season."

How come? Well, off-season training practices may have changed, they suggest. Or from an economics standpoint, they note that a 1993 collective bargaining agreement made player salaries a much more important part of the equation for owners and coaches. "The risk of injuring highly paid veteran players in the preseason may have contributed to the decline in the importance of winning NFL preseason games," they write.

So, once again, science confirms something that everyone suspected, the authors conclude.

"These results serve to confirm the view of many fans and even the commissioner of the NFL, who have expressed discontent with the quality of preseason NFL performance. Although preseason games may provide opportunities for players new to the NFL to experience game-time experience and offer the coaching staff more information on the performance capabilities of new players, winning preseason games does not directly translate into better overall team performance in the regular season. The preseason does offer the owners additional revenue and put the players at added risk for injury."

The same journal does offer another bit of guidance for fans. In an online study, Ohio University researchers find that first week games may be the real practice opportunities. Bettors may have an edge betting against offenses in the first week, that second study suggests.