The first two rounds of the NHL’s Stanley Cup Playoffs are the most-watched in the U.S. in league history.Women are the primary driver of that growth.TNT Sports reported female viewership is up 66% and ESPN reported a 106% increase, with plenty of that audience coming from 18-to-34-year-olds tuning in to hockey at its most exciting time of year. “We see the numbers up everywhere,” ESPN VP of production Linda Schulz said. “(Hockey) is a particular challenge because sports fans tend to follow something that they themselves have participated in and hockey is one that is not as commonplace for people to have actually strapped on skates. I approach it with, if I get a new fan coming to hockey, what is going to keep them.”What’s bringing fans in, Schulz and other executives said, is a result of a handful of factors. The success of the 4 Nations Face-Off tournament last year, the Olympics in February when the U.S. men and women won gold, the quality of play, an influx of young talent and the viral popularity of the “Heated Rivalry” and “Off Campus” hockey romance shows have combined to bring more women to the sport.“It’s not any one thing,” TNT Sports executive VP and chief content officer Craig Barry said. “It’s the collective of the planets aligning that has shown dramatic increases in the female audience.”The NHL says the playoffs are averaging 1.4 million viewers, up 63% from last year and up 24% from the previous high set in 2024. Some of the increase can be attributed to a change in how Nielsen is counting viewers, causing bumps across the board, though hockey has been seeing an upward trend in viewership predating that.That began after the 4 Nations, which NHL commissioner Gary Bettman said caused a viewership increase late in the 2024-25 season and into the playoffs. The Olympics built off that, with the Milan Cortina Games drawing huge ratings.”The Olympics was a cultural moment,” NHL chief operating officer Stephen McArdle said. “We know that Olympic viewership does appeal to those demographics, to that female demographic, and so I think the Olympic bump that we saw was really in part influenced by that female Olympic audience.”How big a role “Heated Rivalry” plays is difficult to measure. Schulz, who grew up as a sports fan in the Boston area, said it does not enter her mind, but the networks and the league are well aware of the conversation going around it.“We know that the fictional series are a gateway to our sport,” McArdle said. “We kno …