Duran discovered the signature pitch by accident during a bullpen session in 2018. This season, he’s thrown the pitch nearly 40% of the time and is holding opponents to a .221 average.

It was 30 minutes after Duran left the mound, and the Phillies readied to head home. Taijuan Walker sat at his locker and whistled Duran’s warm-up song. Duran overheard him and smiled. A few minutes later, Alec Bohm whistled it as he left the clubhouse.

Those four pitches were all splitters as Duran finished out a Phillies comeback victory over the Tigers to take the series opener -- and regain first place in the National League East. In one of the most electrifying games of the year, Duran stole the show in his debut.