(AP Photo/Rick Osentoski)

The NFL is saying that strict enforcement of the illegal contact rules will be a “major” point of officiating emphasis for the 2014 season, and that could mean huge numbers for the league’s elite passers. But how much upside are they likely to see?

When the NFL set their sights on reducing the amount of illegal contact/defensive holding in 2004, there was a huge spike in calls per game over the following two seasons followed by a decline, most likely because defenders adjusted to the new rules.

And since the adjustment period, we have seen a steady rise in passing yards per game.

So what does this mean for the future? Based on how the league adjusted during 2004 and 2005, when penalties called per game were high and the league’s defenders were adjusting, not much.

In 2003, 54.8 percent of plays were passes that yielded 5.8 yards per play. Of those, 3.7 percent were touchdowns and 3.1 percent were intercepted. The following season saw some slight differences in performance.

NFL passing rates

On the same number of passing plays per game the league was averaging more yards and converting more touchdowns in 2004, the first year of the crackdown. Using the same inflation for this season, also year one of an increased focus on penalties, here is what to expect from an average quarterback making 500 pass attempts in 2014, compared with the same in 2013:

qb2013 vs 2014

Inflate Peyton Manning’s 2013 campaign the same way, using 659 attempts from last season, and it becomes 5,759 passing yards, 62 touchdowns and 10 interceptions.

Some receivers will benefit — as will some quarterbacks — but on average, there shouldn’t be much increase in production as a result of more illegal contact/defensive holding penalties.