Examining Michael King’s dominance for New York Yankees

New York Yankees reliever Michael King has turned into one of the best relievers in baseball this season. What has led to this development?

When the New York Yankees acquired Michael King in November 2017, most viewed it as your typical minor offseason transaction. Fast forward five years later, and this trade has become significant for both teams. Garrett Cooper, who the Marlins acquired for King, has been a consistent contributor for Miami since 2019. King on the other hand, has blossomed into one of the best relievers in the League. The question though, is how did an under the radar starting pitching prospect turn into this dominant of a reliever?

In King’s first year with the Yankees organization, he was brilliant as a starter. In 24 starts across three levels that season, King finished with a 1.79 ERA and a 2.76 FIP. In 2019, he made his major league debut, throwing two scoreless innings. He got more of an extended shot in 2020, throwing 26.2 innings, struggling to a 7.76 ERA and 5.14 FIP. In 2021, he began to show significant signs of development. He had a fine season, but his pitch selection changed.

King started throwing a slider 10% of the time, and he pretty much stopped throwing a curveball, a pitch he threw 19% of the time in 2020. He also added a new cutter, which he threw 15% of the time, reducing his sinker usage.

In 2022, the usage of these pitches has changed again. He no longer throws the cutter or curveball, and is throwing his slider 29% of the time now. He also increased his 4 seam fastball usage, up to 24%. In addition to the pitch usage, another thing worth noting is the increase in spin rate for his fastball and slider, with the slider adding 100 RPM’s this year.

That slider has been almost unhittable this season, with hitters struggling to a .132 batting average and .185 wOBA against it. King has also added almost 3 MPH to this slider and 1.5 MPH to his sinker. He credits the development of his slider to Corey Kluber, who he said he learned the grip from.

On the season, Michael King has a 2.38 ERA, 2.31 FIP, and a 2.33 xFIP. His 1.4 fWAR leads all relievers.  He has been completely dominant for the Yankees, being used in a number of roles, including a multi inning role. He’s striking out 12.10 per nine innings, up from 8.81 last season. The Yankees clearly saw something in King when they acquired him, and have developed him into a huge weapon out of their already loaded bullpen. He walks very few people, just 2.81 per 9, which is also a huge contributor to his dominance.

Success stories like these are one of the many reasons the New York Yankees are on pace to have one of the greatest regular seasons of all time.