What’s behind the dramatic drop in U.S. viewership?

National NHL ratings in the U.S. have taken an enormous hit year-over-year, according to a new report from the Sports Business Journal.

The report reveals a concerning 22% year-over-year decrease in viewership, particularly of note given that the NHL is in just the second year of a pair of exclusive seven-year U.S. media rights deals with ESPN and TNT.

In part, the drop is due to an expanded slate of NHL games across each network, the report says. Both ESPN and TNT doubled the number of games broadcasted nationally from 27 to 54 games, which in turn brought along an expected, but nevertheless disappointing, drop in average viewership.

Combined with media blackouts in key regions for TNT and Sunday competition with the NFL for ESPN — neither of which factored into play due to no blackouts or weekend games to this point last year — and the cause behind the significant ratings drop becomes much clearer.

Interestingly, outside of game viewership, ESPN’s partnership with the NHL appears to have made significant strides since last year’s All-Star break. The powerhouse network has reported positive gains in both online and app engagement with the NHL, while social media engagement around the NHL is up a staggering 224% year-over-year, the report says.

In the case of the rise in social media engagement, it seems likely that the introduction of fan voting via Twitter was an enormous success. Fans were able to use tweets, retweets, and hashtags to vote their players into hockey’s mid-season classic.

What else could be causing the ratings dip?

That doesn’t make the NHL’s drop in ratings any less concerning, however, even if they were somewhat expected by the major players. Beyond the report’s findings, other contributors to the league’s loss of viewership on the major networks likely boil down to a few key factors.

As a league composed of highly localized fanbases, at least…