Robin Lehner turned aside 31 shots for his fifth shutout of the season, and with it he etched his name – as well as that of crease partner Thomas Greiss – into the NHL record books.

There’s this Twitter account, not as active as it once was but still in existence, called You Can’t Predict Baseball. Its raison d'être is highlighting those unbelievable, unforeseeable moments that happen from time to time in big-league baseball, or, as succinctly stated by the account’s bio, “Because sometimes Scooter Gennett hits four home runs in a game.” To borrow a line from Slapshot’s Dickie Dunne, that captures the spirit of the thing.

It turns out, though, that it might be harder to predict hockey than it is baseball. After all, who would have guessed that a career backup and a so-so starter who was let walk by a bottom-feeding club would turn out to not only be the best one-two punch in any crease in the NHL this season, but play so well as to put themselves in the conversation for the best single-season pair in league history?

There’s no denying there wasn’t much to love about the New York Islanders’ goaltending duo on paper. In one corner stood Thomas Greiss, who was fresh off of a campaign in which his save percentage fell below .900 and his goals-against average came within perilous reach of eclipsing four. In the other was Robin Lehner, let go by the Sabres as a restricted free agent and in search of his third organization in five seasons after an up-and-down tenure in Buffalo. But the overlooked duo has thrown the rest of the NHL one of the biggest curveballs of the campaign, as Sunday’s effort from Lehner put the Islanders’ keepers in some rare company.

You see, only nine times prior to last night had the league seen a goaltending duo post five shutouts apiece in a single season, but getting the call in the second half of a back-to-back set Sunday, Lehner made himself and Greiss the 10th tandem in NHL history to each post five clean sheets in a campaign. Lehner’s perfect game was pitched against the Arizona Coyotes, as he blanked a hungry team that was in desperate need of points to aid its playoff push. Altogether, he turned aside 31 shots in an A-plus effort that gave him his fifth shutout of the campaign. For Greiss, the fifth shutout had come only two weeks prior, coincidentally also a 31-save shutout, though his against the likewise wild-card contending Columbus Blue Jackets.

For how rare the feat has been, what’s worth noting is that it has happened with an increased frequency over the past decade. In fact, Lehner and Greiss join Craig Anderson and Mike Condon (2016-17 Ottawa Senators), Henrik Lundqvist and Cam Talbot (2014-15 New York Rangers), Brian Elliott and Jaroslav Halak (2011-12 St. Louis Blues) and Tim Thomas and Tuukka Rask (2009-10 Boston Bruins) as duos to post five shutouts each in a single season over the past 10 years. Also included in the post-lockout era is the 2006-07 Nashville Predators’ pairing of Tomas Vokoun and Chris Mason.

There was a sizeable gap between the current era of twin five-shutout keepers that was kicked off by Vokoun and Mason and the past generation to reach the mark, however. More than three decades passed between the Predators’ duo accomplishing the feat and Tony Esposito and Gary Smith achieving the same statistical output with the 1971-72 Chicago Black Hawks. Others to have hit five shutouts apiece include Glenn Hall and Jacques Plante (1968-69 St. Louis Blues), Plante and Gerry McNeil (1953-54 Montreal Canadiens) and Turk Broda and Al Rollins (1950-51 Toronto Maple Leafs).

What sets Lehner and Greiss apart, though, is that while posting shutouts is difficult, it's that much harder to maintain a high caliber night in and night out. In several of the above-listed five-shutout duos, be it the Anderson and Condon-led Senators or the Thomas and Rask-driven Bruins, one of the two netminders lagged somewhat behind in pure statistical excellence. Yet, here are Lehner and Greiss, clipping along with some of the best overall numbers in the league.

To wit, following Sunday’s action, Lehner is among the NHL's top keepers, ranking third in SP (.928) and second in GAA (2.17) among goaltenders with at least 30 games played. Greiss isn’t at all far behind, either. His .926 SP ranks fourth among the same group of netminders, his 2.29 GAA third. No other team has two 40-game goaltenders, let alone a duo with numbers as good as those of Lehner and Greiss. And even when opening it up to those keepers with at least 30 games played, the two Islanders keepers have been significantly better than the next-best tandem, which is the Bruins’ Halak and Rask.

Propelling New York’s crease tag team further up the list of the best single-season performances from a one-two punch, though, is that it’s rare any pair of goaltenders has ever carried a similar workload and produced results this exceptional.

There are 72 instances in NHL history of a team boasting two 40-game goaltenders, but only once since the league’s inception have those two keepers managed to each clear a .925 SP, which is exactly what Lehner and Greiss are in line to do. That came in 1967-68, when the Maple Leafs’ blue paint was patrolled by Johnny Bower and Bruce Gamble. Even when widening the scope to 30-game goaltenders, only three other tandems are included: the Blues’ ’11-12 Elliott and Halak combo and ’68-69 Plante and Hall pairing, as well as the Philadelphia Flyers’ 1967-68 duo of Bernie Parent and Doug Favell. But that’s it. That’s all. The list ends there.

Will either Lehner or Greiss go down as Hall of Famers like Plante and Parent and Bower? There’s next to no chance. But for one season, the duo have proven they can play perfectly off of each other, and with it has come a little slice of history that they can call their own, as well as mention among some of the best single-season goaltending duos the NHL has ever seen.