The Royals have recently seen a resurgence in terms of pitching dominance, with names like the sensational Cole Ragans and the kitchen sink king Seth Lugo on the minds of fantasy managers and Cy Young voters alike. While we have come to expect dominance from these guys on the mound, there is another pitcher who is quietly looking like Kansas City’s next ace.
Kris Bubic has been a revelation this year. For years, the former first-round pick seemed to be another cog in a rather dysfunctional Royals organization. His ERA and WHIP were high, while he rarely struck out any batters. Teams facing him would often go on hit parades, crushing the erratically placed fastballs and hung breaking pitches.
However, as you can tell just by looking at his strikeout and walk rates, a lot has changed in recent seasons.
Bubic was one of those “werewolf” type pitchers early on, putting up an elite night once every full moon. In 2023, he started to settle in and looked to become a legitimate breakout candidate. Like so many other pitchers that year, though, he was struck down by the elbow injury curse. He hit the operating table in late April that season and came back in a relief role in July 2024. Bubic looked incredible down the stretch with the Royals, coming out of the pen and showcasing the swing-and-miss stuff that could make him a go-to guy in high-leverage situations. The Royals saw more in Bubic and brought him to the rotation, where he could show his true value, which he has done in spades.
So what makes Bubic so nasty? Well, it starts with his foundational pitch.
Making the Most of His Fastball
The key to Bubic’s success is similar to many other elite pitchers: an excellent foundational fastball.
Now, you might be shocked to see that the heater sits at around only 92 mph. This is a tick down from last year, though the reliever-to-starter promotion does that. As the table below shows, though, this pitch is getting strikes, and hitters are struggling to make contact off of it.
Think about some of the most daunting starting pitcher fastballs in the game today. You probably immediately think of the 95 mph+ fireballs employed by pitchers like Zack Wheeler, Logan Gilbert, Garrett Crochet, and/or Jacob deGrom. All of these guys throw heat, with excellent extension off the mound, making their pitches even more explosive in the eyes of hitters.
Yet thus far, Bubic has a higher swinging strike rate on the heater than all of these names.
His CSW (Called Strikes + Whiffs) rate is also insane, as he is in the 97th percentile of the stat. This means that his fastball is more effective than 97% of the four-seamers in the game at getting what are perhaps the two most sought-after outcomes on the pitch.
So, how does he do it? In a word: deception.
A deceptive fastball is the key to success for many of the game’s starters who lack the velocity component. Shota Imanaga is maybe the prime example of this, as the fastball became his calling card despite it often hovering around 90mph. Hitters have struggled to make good contact on the heater, swinging and missing and popping up pitches that, in theory, should’ve been easy to time up with.
Like Imanaga, Kris Bubic excels with the fastball due to its shape.
As you can see, Bubic has an excellent IVB and HAVAA. For those unaware of what these mean for Bubic, here’s a quick crash course.
Induced vertical break in the context of four-seam fastballs refers to the perceived vertical “rise” on the pitch. The pitch can’t actually rise due to gravity, but the backspin put on the ball gives it that illusion. iVB measures the vertical distance between the pitch thrown and a hypothetical pitch thrown identically but with no spin.
The other component of Bubic’s fastball’s deception is the flat attack angle it comes in at. This is measured with Height Adjusted Vertical Approach Angle, abbreviated to HAVAA. Now this sounds great and all, but what does it mean? Well, it’s pretty simple. Pitchers stand on a mound that sits above the ground 60 feet and 6 inches away from home plate. Because pitchers are elevated above the hitter, they have to throw downwards to reach the strike zone.
The angle of the pitch’s path from the pitcher’s hand to the batter is the “Vertical Approach Angle”. With four-seam fastballs, flatter angles lead to harder-to-hit fastballs when thrown high in the zone, as the bat and pitch paths intersect less. HAVAA adjusts this angle for a pitcher’s height and scales it to where 1.0 is average. As you can see in the chart, Bubic’s fastball is definitely flatter than average.
It’s also worth noting that Bubic has a well above average extension of 6 feet and 8 inches. As he extends himself further towards the batter, his fastball’s perceived velocity is slightly higher than the 92mph mark that it hits on the gun. This is just another element of the deception caused by Bubic’s fastball.
As incredible as Bubic’s fastball has been, though, it could perhaps be even better if he improved its location. As mentioned before, a flat approach angle allows the fastball to excel at the top of the zone. Bubic’s hitter has been a bit erratic at times, as command is not his specialty. He’s struggled to locate the pitch up in the zone in some starts to its detriment. If he can hit his spots in the top of the zone, then he will unlock even more swings and misses, and pop-ups.
Locations of each swinging strike on Bubic’s fastball
The Slow Stuff
While Bubic has found success with the fastball, he has shown promise with the secondary pitches.
Like many of the game’s nasty lefties (including his rotation-mate Cole Ragans), the changeup is his preferred weapon of choice against opposite-handed batters. Now this changeup isn’t necessarily the type that would win him the Cy Young (like Skubal’s untouchable slowball that earned 28% swinging strikes), but it still gets more whiffs than the average change-piece. It also has a high strike rate, which is good for getting ahead in counts. Interestingly, this pitch has been featured a lot less these past couple of seasons than in previous years, as he’s put more focus on the breaking stuff.
Bubic also features two different sliders. The sweeper is his more frequently used one, as it sees action to both lefties and righties. He really leans into it against lefties, as he uses it nearly 40% of the time against them. The pitch does its job earning strikes and it has an above-average whiff rate for a sweeper. His slider is thrown almost exclusively to lefties, though he has thrown it occasionally to righties. It has been thrown much harder this year than it has been in the past, though his old “slider” was characteristically more like the current sweeper.
The big question will be whether Bubic can improve his command of these pitches. We want to see him execute and hit is spot, and not do whatever you call the recent start against the Rockies, as pictured below:
Though of course, as his stuff is so good, his statline for that game was dominant anyway. Still, it could be even better with improved location.
Kris Bubic has been one of the more exciting breakout pitchers early in the season. We always had an inkling that one day he’d be nasty, but now that we’re seeing it, it’s awesome to watch. His deceptive arsenal has led to him dominating lineups, and it will be exciting to see how close he can get to being an ace by year’s end.
