The evolution of Ian Kennedy from failed starter to lockdown closer

In Arlington on May 30, Ian Kennedy entered the game in the ninth inning with the Royals holding a one run lead. He faced three batters, whiffed two and picked up his third save of the season. We didn’t know it at the time, but at this moment, he was effectively anointed the Royals closer.

Since that outing in Texas, Kennedy has made 22 appearances, all coming in the ninth inning, all but three in a save situation. He has thrown a total of 20.2 innings, allowing 14 hits. He has whiffed 26 batters and walked just six. Opponents are hitting .194 against him and his ERA is 2.18.

He has become the most trusted member of Ned Yost’s bullpen. And with a single blown save over that stretch, he is as automatic as you can hope from your ninth inning reliever.

The Pitches

To understand Ian Kennedy, The Closer, we need to see how his arsenal has evolved over the last couple of seasons, culminating in this move to the bullpen.

In 2017 he threw a higher percentage of sinkers that he had ever thrown in his career—not counting his 2008 season where he made 10 appearances (nine starts) and threw just under 40 innings. The results on that pitch was… not good. In 2017, opposing batters clubbed his sinker to the tune of .534 slugging percentage with an xSLG of .600. It was the highest slugging percentage of all his offerings that summer and he was fortunate it wasn’t higher. The Statcast measured exit velocity on the sinker at 92.2 mph meant it was the hardest-hit pitch of the five he threw on a regular basis.

Kennedy started moving away from the sinker last year, throwing only 24 as measured by Statcast. This year in his move to the bullpen, he has eliminated the pitch completely. He’s also eliminated his slider, a pitch he has generally thrown anywhere from eight to 12 percent of the time, when he has used it on a regular basis. There have been a couple of years (2012 & 2013) where he basically shelved the pitch. And like his sinker, he largely eschewed the slider last year, throwing it less than two percent of the time.

So with the sinker and the slider on the way out last summer, it made sense that as he transitioned to the bullpen those pitches would be left behind. As a reliever, he’s evolved into basically a three pitch pitcher: Fastball, curve and cutter, with an occasional change-up mixed in.

Focus on the Fastball

Kennedy’s four-seamer has always featured plenty of run. In fact, from 2015 to 2017, his fastball averaged around 12 inches of horizontal movement, close to 40 percent above the league average movement on the heater. That number tumbled to 8.6 inches of horizontal run last year. It has rebounded to 9.8 inches this year, 20 percent more than the league average on the fastball.

While it’s interesting that he’s regained some of the movement he lost last year, that doesn’t really tell us how he’s been so successful with the four-seamer. After all, he had much more break in each of the seasons from 2015 to 2017 and the results were underwhelming. This year, the fastball is Kennedy’s best pitch.

One difference is obvious. Coming from the bullpen, he’s able to air it out much more than if he was pacing himself to go deep into games as a starter. According to Statcast in the last four years Kennedy’s four-seamer has averaged around 92 mph. This year, he’s found two extra mph and is clocking, on average, 94.1 mph with the heater. That’s substantial, but not unexpected.

What is unexpected is the increase in spin rate on Kennedy’s fastball.

Kennedy has also altered his spin axis by dropping his arm slot. As noted on the Driveline Baseball blog, the run of the fastball will be affected by arm slot, which impacts the spin axis. A pitcher who throws over the top will feature a nearly horizontal spin axis, or more “rise.” The lower the arm slot drops, the more a vertical spin axis, or arm-side run.

The best way to illustrate the change in Kennedy’s delivery and the impact on his pitches is through video. Here is a clip from last year where Kennedy uncorks a 94 mph fastball to strikeout Chris Davis in Baltimore.

Kennedy didn’t usually throw that hard last year, but context—he had allowed three first inning runs after being spotted a four run lead in the top of the frame—matters. Most importantly, not the arm slot and the slight arm-side run on the fastball.

Contrast that to what we see regularly from Kennedy in 2019:

The arm slot is lower and the run to the arm-side is a little more pronounced. It’s a more difficult pitch to hit.

Brooks Baseball provides the confirmation that Kennedy has dropped his arm slot by a couple of inches.

The deception of the lower arm angle and the affect of the movement in his fastball has made Kennedy more difficult to square up. Yes, the fastball is spinning more than before, but the real benefit comes from a more efficient and deceptive spin.

The secondary pitches

While the four-seamer has evolved into a killer pitch for Kennedy, the curve and cutter are nowhere near as effective. He is allowing a .378 BA on his curve and both home runs he has allowed this year have been hit off the pitch. Although with a .201 xBA against the curve, the advanced Statcast metrics suggest Kennedy has had some misfortune when the ball has been put into play. He’s getting more swings and misses against his curve and when he throws it when he’s ahead in the count, it’s an effective counterbalance to the heater.

He’s not missing as many bats with the cutter (only one plate appearance that has ended on the cutter has been a strikeout, but it’s a pitch he mostly uses against right-handed hitters, and rarely when he’s ahead in the count. Kennedy shows it 31 percent of the time on the first pitch to righties.

The results

The net result of the increased velocity, altered spin axis, and the mix of pitches has made Kennedy a much more effective pitcher. His average exit velocity is down to 87.1 mph, the lowest of his Statcast seasons (going back to 2015) by 1 mph. His average launch angle is 12.9 degrees, over four degrees lower than last year and nearly five full degrees down from his high in 2016.

The question is, is this sustainable? Can we expect Kennedy to continue to shove out of the bullpen? The short-term answer is yes. At least as much as we can expect for a 34 year old with over 1,700 major league innings on his arm. That means for the next two months, he will continue to be the most reliable reliever in the Royals’ bullpen. The lockdown closer. Of course, with the Royals still on pace for 100 losses, it ultimately doesn’t matter. With the trade deadline Wednesday, a savvy contender would check in on Kennedy’s availability. Of course, the Royals reluctance to cover any part of Kennedy’s salary means there’s minimal traction here. That means the club will go into 2020 with their closer position settled at a hefty $16.5 million.

That’s an exorbitant amount of money for a ninth inning specialist, especially for a small-market team like the Royals. (Only three closers make more this year: Kenley Jansen, Wade Davis and Aroldis Chapman.) While I’m less optimistic the results from 2019 will carry over into the following season (such is the unpredictability of closers) there still may be opportunity for the Royals to get out from under some of the money owed. But it all depends on the adjustments made this year taking root and becoming a factor again next season.