During the offseason the NFL made the decision to enforce offensive holding penalties more strictly going forward. While this was certainly noteworthy, the NFL does have a history of emphasizing specific penalties prior to the season and throughout the preseason, only to see those flags return to status quo once the real games begin.
However, according to ESPN's Kevin Seifert, that has not been the case through two weeks of the 2019 NFL season.
There have been 92 flags for offensive holding in Week 2, per @ESPNStatsInfo. For comparison, there were 45 in Week 2 last year. Largely the result of point of emphasis on backside blocking.
Week 1-2, 2019: 174
Week 1-2, 2018: 107— Kevin Seifert (@SeifertESPN) September 16, 2019
According to Seifert, this has also resulted in a drop in scoring from 21.97 offensive points per game in 2018 to 20.9 so far this season.
From a football betting perspective, this may be having an effect on over/unders as well.
Last season, unders went 15-17 (46.9%) in Weeks 1-2 according to Bet Labs. In comparison, 20 of 32 (62.5%) of games have gone under so far this season.
In fact, unders are off to their best start since 2006 in terms of win percentage through the first two weeks.
Here's a look at the winning percentage for unders in Weeks 1 and 2 since the start of the 2005 season.
Overall, unders are 248-223-7 (52.7%) over the entire sample, so there is a trend toward the under early in the NFL season.
Even so, it's reasonable to assume that the spike in holding calls has done enough to hinder offenses this season compared to years past, which, in turn, has rippled to over/unders as well.