When Carl Edwards Jr. got Jose Ramirez to ground out to crown the Chicago Cubs champions of Major League Baseball, the world learned that the Cubs had just broken a 108 year curse–the longest championship drought in professional sports. They learned that Cubs General Manager Theo Epstein had created a youthful juggernaut that dominated the MLB season wire-to-wire and is poised to be baseball’s next great dynasty. They might have even learned of the Cleveland Indians, who blew a 3-1 series lead in much the same way as the hometown Cleveland Cavaliers came back from one. However, what the world did not learn was that this World Series represented a fundamental shift in the philosophy of professional baseball, potentially changing the nature of the game for decades to come.

23. That’s the number of outs Indians reliever Andrew Miller–widely regarded as the best relief pitcher in baseball–recorded this World Series. 0. That’s the number of outs that came in the ninth inning. Ask any casual baseball fan and they will tell you that a team’s best relief pitcher is designated as their closer, consigned almost exclusively to recording three outs in the ninth inning of games that their team leads by three or fewer runs. For years, baseball has operated on this paradigm–managers, fans, and players alike. It provided a kind of safety net for teams; a way to ensure that their hard-fought victories would not be blown in the ninth inning by inexperienced and overmatched relief pitchers.

However, with the rise of data analytics in sports, this approach has been increasingly questioned. Five Thirty Eight wrote an article earlier this year detailing the utter hypocrisy of the role of a traditional closer. In an era where every statistical advantage is sought to be maximized, it argued that confining premier relief pitchers to recording often unimportant outs in games when other situations existed of much higher importance and urgency was one area where baseball was hopelessly stuck in the past. This kind of thinking, though, was mostly rejected by baseball’s managers–many members of that old guard themselves–who continued to use their closers traditionally, potentially costing themselves dozens of wins over the years.

That is, until this postseason rolled around. Going into this postseason, it was clear that both the Cubs and Indians understood the value of dominant bullpen arms, evidenced no more obviously by their moves at the trade deadline. Both teams traded for premier relief pitchers–both from the New York Yankees–as the Cubs acquired fireballing Aroldis Chapman and the Indians received Miller, both in exchange for top prospects. Thus, it was on the backs of these relievers that both teams conquered their respective leagues and made it to the World Series. But then, on baseball’s grandest stage, these two teams showed their competitors exactly what the future of relief pitching looks like.

While Indians manager Terry Francona had used Miller in a versatile role during the regular season and earlier in the postseason, what was done in the World Series was unprecedented. Miller entered twice in the fifth, twice in the seventh, and not once recorded an out later than the eighth. Conversely, Chapman was used slightly more traditionally, entering no earlier than the seventh, but threw 5 and a third innings over the last three games and did not record a save, despite four Cub victories. This form of relief pitching–popularly coined as “fireman” relief pitching, as the relievers were often summoned to come in to put out “fires” on the bases–propelled both teams throughout the series, both enabling rallies and suffocating them.

It is perhaps fitting to consider, however, that this method of high-leverage relief pitching for multiple innings at a time is not a novel concept. For decades leading up to the 1970s, the idea of having designated relief pitchers was unheard of in baseball, as starters were expected to start and finish games by their own volition. During the 70s and 80s, though, it became clear to managers that there was value in employing fresh arms later in games–typically hard throwers who could get much-needed outs with runners on base. Thus, the relief pitchers of this era were the original firemen, inserted to replace struggling starting pitchers and quell dangerous situations in high-leverage moments. It is ironic, then, to think that as baseball has supposedly gotten more and more advanced, with teams looking in every direction to find even the subtlest of competitive advantages, in terms of situational pitching, optimization will come not by looking forward, but by looking back.

So what does this mean for the future of the game? Likely a lot. It is no secret that teams look to World Series champions as blueprints for success, representative of teams that truly transcend in an era of only increasing parity. Following Yankees triumphs, this meant freer pocket books and more lucrative free agent contracts. A Marlins victory in 2003 (and subsequent crash after) highlighted the value in both developing and controlling young talent. A Royals-Giants dynasty of late re-emphasized small ball and situational hitting in baseball. In all of these situations, teams across the league played copy-cat, trying to mold their squads to the image of recent champs. Ergo, the theme that emerges out of this World Series is likely to be the value of prime relief pitching at prime moments, a concept that despite its seeming simplicity has proven elusive to league wide adoption.

A shift as such over the next couple of years thus has the potential to completely redefine the game, bringing long-neglected relief pitching to prominence across the league and creating death panels for rallies in the late-innings.