Robert Stephenson isn’t the closer for the Cincinnati Reds and he’s a failed starting pitcher. His earned run averages of 6.08, 4.68 and 9.26 ERA from 2016 to 2018 respectively, primarily as a starter, indicate that. Last year, he didn’t notch a save or make a single start, posting a 3-2 record with an 11.27 K/9, 68.0 percent strand rate, and a 3.76 ERA. Aside from the strikeouts, which helped him be valuable last year, there doesn’t seem to be much to get excited about with Stephenson. However, a change to his repertoire unleashed one of the game’s deadliest pitches in 2019.

Per FanGraphs’ pitch value metric, counting only relievers who accrued enough innings to qualify, there were four pitches that posted a pitch value higher than 17. Three of them were fastballs (Seth Lugo , Aaron Bummer , Trevor May ), but the only non-fastball to surpass the aforementioned mark was Stephenson’s slider. He’s had a good slider, but one could argue he didn’t use it enough. Despite allowing a...