Cardinals All Star reliever Ryan Helsley has been one of the best bullpen arms in baseball so far this season. Even the most optimistic of Cardinals fans couldn’t have seen this coming from a pitcher who posted a 4.46 FIP, amassed a 0.1 WAR and walked 4.4 batters per nine over the past three seasons. There was a chance Helsley wouldn’t even be on the team this season after posting back-to-back seasons with an ERA above 4.50 with a negative WAR in both of those seasons. So how has Helsley gone from a below average arm to one of the best in such a short period of time?
Halsey has almost doubled his strikeout rate going from 22.8 percent to 41.9 percent and reduced his walk rate from 13.1 percent to 8.1 percent. The walk rate is still below average as it sits in the 44th percentile but with a strikeout percentage in the 99th percentile it is something that you can pretty easily overlook. As a result of one of the best K percentages in the league Helsley also has some of the best expected numbers across the board. His xBA of .144 is in the 100th percentile whilst his xSLG of .249 and xWOBA of .210 sit in the 99th percentile. Helsley’s average exit velocity against is 90.2 which is in the 15th lowest percentile, but when you throw as hard as he does naturally you are going to allow an elevated exit velocity.
The key to the All-Star’s evolution as a player comes in both his pitch release and quality of pitch. His four-seam fastball velocity has gone up from 97.4 miles per hour to 99.1 with its spin rate going from 2,526 to 2,632. His slider’s spin rate and velocity has largely stayed the same as with his curveball, although he is incorporating his curveball more this season, throwing it 9.9 percent of the time compared to last season’s mark of 6.8 percent. The biggest change in Helsey’s game though is his extension. Last season he was releasing his four seamer and slider at 6.5 feet and his curveball at 6.4 feet. This season’s extension on his fastball and slider is 6.7 feet and his curveball is 6.6 feet. So not only is Helsley throwing his four seamer over a mile per hour harder than last season he is also releasing it closer to the plate which gives it a higher perceived velocity.
In terms of his batted ball profile Helsley does a great job of getting hitters to work under the ball because of where he pitches in the zone. His pop-up percentage has gone up from 9.1 percent to 13.5 percent which is almost double league average. Additionally, his under percentage has gone from 25 percent to 36.5 percent which is 12.3 better than average.
In terms of plate discipline against this year Helsley has been one of the better pitchers in baseball. His zone contact percentage has gone from 82 percent down to 73.8 percent which is 8.2 percent better than league average. His chase contact percentage of 34.5 percent is 23.9 percent better than average and 12 percent better than his mark from last season. Additionally, his whiff percentage of 39.2 percent falls into the 99th percentile and is 14.6 percent better than league average.
Most importantly, as good as Helsley has been this season, there is not anything that indicates things are suddenly going to take a turn for the worst for the flamethrower. Relievers are inconsistent on a year-to-year basis so there is no guarantee he can repeat this performance next year, but for now we can all sit back and relax in the late innings because the Cardinals have one of the most reliable relievers in baseball.