Ryan Heffernon mused on Kyle Isbel’s role on the 2025 Royals just a few weeks ago, coming to the conclusion that his good-but-not-great defense does not quite outweigh his lack of bat. He compared Isbel against such defensive wizards as Michael A Taylor, Billy Hamilton, and Kevin Kiermaier, whose contributions on defense made up for the lack of bat to produce average-to-above-average seasons by fWAR.
And…yeah. We have 1100 MLB plate appearances amounting to a 77 wRC+ and 3.5 fWAR across parts of four MLB seasons. He’s actually slightly improved his wRC+ each of the past two seasons, but “slightly improved”, to Ryan’s point, may not be enough.
But one thing I noticed was his baserunning value (BsR); it has also gone up each of the past two seasons. I know, I know – plate appearances, playing time, sample size, blah blah blah. If you take his BsR value and turn it into a rate, the same conclusion applies. And that’s without stealing many bases. Naturally, this raises a question: could Isbel have room for more baserunning value to help make up for the good-but-not-great defense?
Let’s start with understanding his raw speed tool first. According to MLB Savant, his sprint speed is in the 65th percentile. Thankfully, the Royals have some guys who steal a lot of bases against which we can compare.
We all know Bobby Witt Jr. Dude’s fast. MLB Savant lists his sprint speed as the 100th percentile (lol). Dairon Blanco’s also fast – 97th percentile. Maikel Garcia, though, is the guy who actually led the Royals in stolen bases in 2024 with 37. His sprint speed is in the 66th percentile, right next to Isbel.
However, sprint speed is only one factor for stolen bases. Acceleration/burst is another. A guy’s gotta go from a standstill to full speed as fast as possible for a better chance of success. MLB Savant wonderfully gives us splits that can give us a rough approximation of acceleration. They have splits for every five feet on what looks like 90 foot measurements. On that metric, Isbel excels.
I used the five-foot splits to compare Isbel, Garcia, Blanco, and Witt in terms of velocity and acceleration (I really hope this is not confounded by Isbel being a left-handed hitter). Compared to these guys, whose sprint speed is much higher (Witt, Blanco) or about the same (Garcia), Isbel’s acceleration burst is the best.
Isbel’s acceleration kicks off at 17.8 ft/s^2 (feet-per-second squared) in the first 5 feet. Garcia is at 15.94, and Witt/Blanco are both at 16.53. At about 25 feet in, Isbel’s acceleration slows down compared to the other three. However, as a result of the initial burst, Witt and Blanco don’t catch up to Isbel’s velocity until about 40 feet in, and they don’t overtake him until 50 feet. Maikel Garcia actually never overtakes Isbel’s velocity. This makes me think that Isbel really does have room to grow into stealing more bases. He just turned 28 and should still have his speed for another couple seasons. His burst is well within the bounds of the other Royals base-stealers, if not better.
Obviously, yeah, there’s more to stealing bases than acceleration and sprint speed. But, comparing guys with different speeds on the same team with the same coaching helps give us an apples-to-apples comparison, as best as we can get, to determine if Isbel has room to grow here. This is where coaching and strategy need to come in.
MLB Savant breaks apart baserunning contributions into a base-stealing component and an extra bases-taken component. On the base-stealing component, there is a measurement showing the average lead on stolen base attempts. There are some differences showing up in 2024. Garcia, having the slowest acceleration of the group, takes the largest lead at 13.1 feet on actual stolen base attempts. Witt, relying on his elite speed, takes the smallest average lead on attempts at just 9.4 feet. Garcia had a 95% success rate last year, and Witt had a 72% success rate. I think maybe Witt has the most room to grow here…dude also gets picked off a lot. Maybe he should take a larger lead? Isbel was right in between at 85% and an average lead of 10.2 on stolen base attempts. Blanco’s at 82% and 11.0 average lead. Given his comparison to Garcia, I think Isbel could probably squeeze another foot or two out of his leads to attempt more stolen bases. That’s a simple coaching point to help him recognize tells of when to dive back or when to go.
There is also a metric showing the percentage of opportunities that actually had a stolen base attempt. Isbel is the lowest of the group in 2024 at only 2.2%. Garcia was at 4.4%, Witt was at 2.7%, and Blanco was at 8.7%. Given the acceleration I already talked about, they could probably send Isbel a bit more.
The other component, the extra bases component, honestly doesn’t seem like there’s much improvement to be gained. He already attempts and successfully takes the extra base at a high rate compared to his other speedy brethren on the Royals. Most of his baserunning value already comes from taking the extra base.
Look – given the burst and good speed Isbel has, the raw ingredients are there. If Isbel is to squeeze more value out of his skillset without his bat improving much, attempting more stolen bases seems like the obvious place to start. He could attempt more of them and take a bit larger lead to do so, and then let his elite acceleration do the rest. In a season of playoff expectations, every little edge helps.