He posted a 3.20 ERA over 56.1 innings for both the Rangers and the Phillies. While it is true he over-performed his FIP and that his Statcast Page is filled with blue circles, he has repeated this success with a 3.27 ERA in 41.1 innings pitched this season. Kennedy is benefiting from luck, as he allows hard contact and his expected ERA according to Statcast is 4.92. However, his results are good and it is in part due to his repeated usage of the fastball.

The Fastball

At 93.4 MPH average velocity Ian Kennedy’s fastball is the 304th fastest four-seam fastball according to Statcast. Despite this, he has the second highest percentage of four-seam usage on the Statcast leaderboard trailing only Jose Quintana. The main reason for his fastball working is the only dark red circle on his Statcast page, a 91st percentile fastball spin rate. His four-seamer has above-average movement in both the horizontal and vertical directions. This is how he can get outs despite his below-average velocity. He primarily throws his fastball inside regardless of what side of the plate the batter is on. Despite his fastball allowing a 48.5% hard-hit rate and a .349 xwOBA, it has generated a -9 run value this season by Statcast metrics. The fastball has a 17% whiff rate and an 18% K rate, neither of which is an especially good percentage. His overall whiff rate is in the 9th percentile, making it one of the worst in the league.

Generating outs

While his overall strikeout rate is below average in the 35th percentile, the key to his fastball working is that it simply generates outs (obviously). Kennedy’s success largely depends on luck, as his .261 BABIP and 9.4 HR/FB rate would suggest, but his over-performance has resulted in a productive relief season. An example of this luck is from August 23, 2022, when Kennedy got a 101 mph and 378-foot flyout against Micheal Massey of the Royals, Shane McClanahan style (Video Here). On August 21st Ian Kennedy struck out Nolan Gorman with an inside fastball (Video) and on August 16th he allowed a walk-off home run to Brandon Crawford on a slightly less inside fastball (Video). In all three of the videos I noticed that the catcher was set up on the outside corner, but the pitch was down the middle or inside to the lefty batter. It ended up working on 2 of the 3 attempts but when he missed over the middle it did not. This could just be a coincidence but is more evidence of how Kennedy is often getting lucky and simply relying on his fastball's elite spin rate.

Results

Ian Kennedy should not have good numbers, he doesn’t miss bats that often and allows hard contact that is more often in the air than on the ground. But because of assistance from his defense behind him and good framing by his catcher, his traditional statistics are able to over-perform their projections. Ian Kennedy is a prime example of how elite spin rate and above-average defense combined with some luck can result in a reliever or any pitcher far over-performing what is expected of them.