The Stanley Cup Final, which begins Wednesday night in Tampa, should be a terrific series for hockey die-hards. The Tampa Bay Lightning play relentless hockey, skating well and shooting well, and led the NHL in goals per game during the regular season. Their opponents, the Chicago Blackhawks, are a fast team and led the league in shots on goal with their precision passing and star talent. What’s more, both teams are relatively healthy despite the grueling playoff chase they’ve endured. The Blackhawks are betting favorites in the series, but only barely.The thing about the NHL in the United States, though — Canada is totally different — is that it’s very much a local sport. There aren’t a lot of NHL die-hards: There are Blackhawks die-hards and Boston Bruins die-hards and Detroit Red Wings die-hards and, though fewer, Tampa Bay Lightning die-hards.This is evident in past TV ratings for the Stanley Cup Final. Since NBC and its affiliates took over U.S. coverage in 2006, the series-average rating has been as high as 3.4, when the Blackhawks played another popular American team, the Philadelphia Flyers, and as low as 1.2, when the Ottawa Senators played the Anaheim Ducks. That’s a pretty wide spread: nearly a threefold ratings difference.There’s not that much mystery to this. You can estimate NBC’s Stanley Cup ratings quite accurately1In the regression analysis, the coefficient of determination is 0.84. based on three factors. First, what game of the series it is — ratings increase the further you go, especially in Game 7.2In the regression, the ratings increase as the series advances is modeled with the exponential function. Second, whether NBC broadcast the game on its flagship network or on a cable channel like NBCSN. And third and most important, the combined number of NHL fans the two Stanley Cup Final participants have in their local markets, as based on my previous estimates.Since we’re looking at only U.S. ratings, Canadian teams are treated as having no local market. Keep in mind that Canada has at least as many NHL fans as the U.S. despite its much smaller population, however. Game 7 of the 2011 Stanley Cup Final, between a popular American team (the Bruins) and a Canadian team (the Vancouver Canucks), featured about 8.5 million American viewers and 8.8 million Canadian viewers.Here’s how the formula, which is based on regression analysis, estimates that NBC will do in the U.S. with the Blackhawks-Lightning matchup (the margin of error on the game-by-game estimates is about plus or minus 1.0 ratings points).The Blackhawks are a pretty good draw for NBC. Among U.S.-based NHL teams, they have the fourth-largest fan base. The Lightning, however, are sixth from the bottom. It’s roughly an average matchup for NBC, and the series is liable to get about average ratings: probably in the neighborhood of 2.5 for the first two games, 1.5 for Games 3 and 4 on NBCSN, and then 3.0 or higher if the series makes it to Game 5 and beyond.But what if the New York Rangers had beaten the Lightning instead of not showing up for Game 7, like the Carl Hagelin jersey that was mailed to my apartment two days too late? (I’m not bitter.3Yes I am.) That would be the best possible matchup for NBC. Among U.S.-based teams, the Blackhawks have the best local hockey market in the Western Conference, while the Rangers have the best one in the Eastern Conference (despite sharing it with two other teams). Ratings would likely have been well into the 3s for the series, with a potentially massive number — the model estimates it at 5.8 — in the event of a Game 7.By contrast, a final between the Lightning and Anaheim Ducks wouldn’t have gotten a great rating. And one between two Canadian teams might have gotten only about half as many U.S. viewers as Blackhawks-Lightning.This poses some interesting questions for the NHL. The league isn’t all that dependent on its American TV rights — instead, it’s real cash cows are from ticket sales and its Canadian TV contract. But recent Stanley Cup Finals have featured appearances by plenty of popular American teams, like the Blackhawks, Bruins, Flyers, Rangers, Red Wings and Pittsburgh Penguins. One downside of expansion into smaller American markets is that it would reduce the chance for one of the popular teams to make a deep playoff run, possibly reducing the long-term value of the NHL’s American TV rights as a result.CORRECTION (June 3, 10:42 p.m.): A previous version of this article incorrectly identified one of the teams in the Stanley Cup Final matchup with a 3.4 series-average TV rating in the United States. The Philadelphia Flyers faced the Chicago Blackhawks in that series, not the Boston Bruins.