It wasn’t easy, but the Pittsburgh Penguins kept their bid for a second-consecutive Stanley Cup alive on Thursday night, surviving the surprising Ottawa Senators with a double-overtime win in Game 7 of the Eastern Conference finals. On paper, there was little reason to think the Sens would pose much of a threat to the defending champs, let alone take them into the 85th minute of Game 7. But that’s the way things have been for Pittsburgh all playoffs long.Chris Kunitz’s game-winning goal saved Pittsburgh from what would have been the biggest conference-finals upset since 1996, when the Florida Panthers knocked off a very different version of the Penguins. According to Hockey-Reference.com’s Simple Rating System (SRS), Pittsburgh ranked fourth in the league during the regular season (0.59 goals per game better than average), while Ottawa ranked a distant 18th (0.01 goals per game below average).1In 1996, the Pens ranked third and the Panthers ranked eighth, though the gap between the two teams — 0.6 goals — was just as big as the gap between Pittsburgh and Ottawa this season.It was the second series in a row that Pittsburgh has been taken the distance by its opponent, after Washington pushed them to seven games in the conference semifinal. To their credit, the Penguins weathered each onslaught; they even outgunned the Sens by 45 combined shots in the East final, including 49 over the series’ final four games. But Pittsburgh has also been living dangerously. Its even-strength possession metrics over the entire playoffs are not as good as they were during last year’s run to the Cup final, nor do they compare well with the postseason numbers of the Penguins’ upcoming opponent, the Nashville Predators.The Preds didn’t play particularly great hockey during the regular season — they ranked 13th in SRS (in part because brilliant defenseman P.K. Subban missed 16 games with an injury). But they’ve saved their best work for the playoffs, where they rank second in possession rate (Pittsburgh is 12th out of 16 teams) and first in SRS2Playoff SRS is calculated by adjusting each team’s playoff goal differential for the regular-season SRS ratings of the teams they’ve played, with a home-ice advantage adjustment to account for where each game was played. (Pittsburgh is second). Pittsburgh was better in the regular season, but Nashville’s been the hotter team of late.So which situation would you rather be in, heading into next week’s series? Intuition might say it’s better to be the comparatively less worn-down Preds, rolling with the more impressive postseason stats. But history suggests otherwise. Going back to 1988,3The earliest season of data in Hockey-Reference’s indispensable game finder tool. there have been 14 cases in which one Stanley Cup finalist had the better regular-season SRS, but its opponent had the superior SRS in the playoffs leading up to the final.414 other times, SRS from both the regular season and postseason agreed who the better team was; those clear favorites won their series 79 percent of the time. Of those, the better regular-season team won the Cup nine times (64 percent). And that’s not even considering that the Penguins’ regular-season edge was slightly wider than the typical favorite’s, or that they’ll have home-ice advantage in the final.If we’ve learned anything about the Penguins these playoffs, it’s that they rarely make things easy. (And if we’ve learned anything about the NHL since 1998, it’s that repeating as a champion is really hard.) But a grueling, complicated postseason run isn’t necessarily a handicap in the Stanley Cup Final, if you’ve had a championship track record all season long.