The Runners Who Make the Least of Their Legs

Rick Osentoski-USA TODAY Sports

Carlos Correa seems like he should be a good baserunner. He’s a young shortstop with great instincts in the field. He’s tall and lean, with a long pair of legs. In his rookie season, he stole 32 bases in 37 attempts across Double-A, Triple-A, and the majors. Yet despite what you’d think, Correa is decidedly not a good baserunner. In fact, he’s been the least valuable runner in the game this season. Over the past two years, he has been worth -13.6 baserunning runs (BsR); only Christian Vázquez (-14.0 BsR) has been worse. Surrounded by catchers, first basemen, and aging veterans, Correa is a fish out of water at the bottom of the BsR leaderboards.

The Twins shortstop recently opened up about his baserunning to Do-Hyoung Park of MLB.com, calling himself “slow as f–k.” It’s no surprise Correa is down on himself amid a career-worst season. Moreover, in a textual medium, it’s hard to gauge just how tongue-in-cheek his comment was. Still, whether he was dramatizing, joking, or a bit of both, it’s worth clarifying that Correa isn’t quite that slow. His sprint speed, as measured by Statcast, ranks in the 34th percentile – slow, sure, but it’s not like he’s walking around the bases. There are 177 players with a slower sprint speed this season (min. 10 opportunities) and 115 with a slower home-to-first time. If Correa is “slow as f–k,” I don’t even want to know what expletives he’d use to describe Miguel Cabrera and Yasmani Grandal. Correa may not have much speed to work with, but even so, his problem is that he isn’t making the most of the speed he’s got.

Correa isn’t the only player guilty of squandering speed, either. Indeed, there are much faster players who have hurt their teams on the basepaths this season, guys who can’t rely on the “slow as f–k” defense. Inspired by Correa’s comments, I looked at the sprint speed for the 50 worst players by BsR this season and took note of some interesting names. I also conducted my search the other way around, checking out the BsR for each of the 50 fastest runners by sprint speed. These are the guys who stood out.

The first category of poor baserunners is the genuinely fast group. Judging by their sprint speeds, these guys should be providing positive value on the bases, yet that hasn’t been the case. Amed Rosario and Travis Jankowski have been non-factors, while Matt Vierling and Ezequiel Duran have cost their clubs several runs with poor baserunning decisions. Here is a quick look at all of their baserunning numbers this year. I’ve included sprint speed and BsR, as well as the baserunning statistics from several other sources, to show that BsR isn’t the only metric that’s down on their legs:

The Legitimate Speedsters
Player Sprint Speed Percentile BsR Rbaser BRR Baserunning (Savant)
Matt Vierling 93rd -3.3 -2 -2.2 0
Ezequiel Duran 91st -3.3 -2 -2.5 -2
Amed Rosario 95th -0.6 2 1.8 -1
Travis Jankowski 91st 0 2 -0.3 0
Rbaser via Baseball Reference, BRR via Baseball Prospectus, Sprint Speed and Baserunning via Baseball Savant

Whenever I find a player with such a significant discrepancy between his sprint speed and baserunning numbers, the next things I look at are his home-to-first time and his 90-foot splits:

The Legitimate Speedsters (Home-to-First, 90-Foot Splits)
Player Sprint Speed Percentile HP to 1B Percentile 90-ft Split Percentile
Matt Vierling 93rd 67th 71st
Ezequiel Duran 91st 86th 81st
Amed Rosario 95th 93rd 74th
Travis Jankowski 91st 93rd 98th
SOURCE: Baseball Savant

These are two other metrics Savant provides to measure speed, and while sprint speed gets all the glory, these numbers can be telling too. After all, there’s more than one way to be a good (or bad) runner – there’s a reason the Olympics has eight different running events. Vierling may have 93rd-percentile sprint speed, but his home-to-first time is closer to average than elite. That still isn’t enough to explain his -3.3 BsR, but it uncovers a piece of the puzzle. As for Jankowski, this extra data makes his middling BsR even stranger; you can count the number of players with a faster home-to-first time (min. 10 opportunities) on one hand.

It’s also critical to look at the components of BsR to see how, exactly, each of these runners is hurting his team:

The Legitimate Speedsters (BsR Components)
Player UBR wGDP wSB
Matt Vierling -0.1 -0.9 -2.3
Ezequiel Duran -3.0 0.5 -0.8
Amed Rosario -1.1 -0.6 1.1
Travis Jankowski -3.4 0.8 2.6

Vierling, as you can see, has caused the vast majority of his damage on stolen base attempts. He is 5-for-11 on the year; no runner with more than five attempts has been successful less often. On the plus side, four of his failed attempts came in April, and he hasn’t attempted more than a single steal in a month since. Thus, he accumulated nearly as much negative baserunning value in his first 23 contests as he has in the 84 games since. However, it would be a much better use of his speed if he could learn to steal bases more efficiently instead of just giving up the pursuit:

For the other three, Ultimate Base Running (UBR) is the component weighing down their baserunning value. The numbers at Baseball Reference are kinder to Rosario and Jankowski; by Run Scoring percentage (RS%) and Extra Bases Taken percentage (XBT%), they have produced at an above-average rate. However, the numbers from Baseball Prospectus suggest Rosario has been below average at advancing on fly balls, while Jankowski has cost his team runs on hits and grounders.

According to Baseball Savant, Rosario attempts to advance far more often than the average runner, and his successful advances haven’t been enough to outweigh his mistakes. Among the 24 qualified runners who attempt to advance 10% more often than average, only three have a lower success rate than Rosario. On top of that, he has had a greater number of advancement opportunities (125) than all of those other 23 runners, so he has cost his teams more runs getting gunned down than any of them:

Meanwhile, Jankowski doesn’t attempt to advance as often as a runner with his speed should. Combine that with his surprisingly low number of advancement opportunities (60), and he just hasn’t had much of an impact on the bases. Savant estimates he has cost the Rangers more than half a run across seven different instances in which he held up at third base instead of going for home:

As for Duran, the various metrics more widely agree he’s been a liability. His XBT% is well below average, and according to Baseball Prospectus, he has cost his team runs on hits, groundballs, fly outs, and stolen base attempts. Moreover, the numbers at Savant suggest he doesn’t attempt to advance as often as he should, nor is he safe as often as he needs to be.

Thus, he is the biggest culprit of squandering elite sprint speed. Vierling lacks stolen base know-how, Rosario is too aggressive, and Jankowski isn’t aggressive enough. Duran, unfortunately, just can’t seem to get any of it right. Despite 92nd-percentile sprint speed, he has had negative BsR in eight out of nine months of his big league career:

Next up, we have Teoscar Hernández, who I’m placing in a category of his own. He doesn’t fly around the bases, but he’s still a plus runner. In fact, one might say he’s faster than he has any right to be. As a slugging corner outfielder with some dreadful defensive metrics throughout his career, he’s not someone you’d expect to have 82nd-percentile sprint speed – especially not in his age-30 season. More to the point, it’s hard to believe he can move that well when he’s been so unproductive on the bases this year:

Teoscar Hernández
Sprint Speed Percentile BsR Rbaser BRR Baserunning (Savant)
82nd -3.9 -1 -0.9 -4
Rbaser via Baseball Reference, BRR via Baseball Prospectus, Sprint Speed and Baserunning via Baseball Savant

Like Vierling, Hernández isn’t quite as fast as his sprint speed would have you believe. According to the College Board, his sprint speed percentile would earn him a B-, while his 90-foot split time would receive a failing grade:

Teoscar Hernández (Home-to-First, 90-Foot Splits)
Sprint Speed Percentile HP to 1B Percentile 90-ft Split Percentile
82nd 76th 62nd
SOURCE: Baseball Savant

Still, there’s no reason Hernández should be such a liability, and yet by UBR, he has been the third-worst runner in baseball. The only less productive players have been Corey Seager (25th-percentile sprint speed) and Grandal (1st-percentile). Hernández has actually done a good job avoiding double plays this year (compared to his -2.3 wGDP last season), but his negative UBR far outweighs any positives:

Teoscar Hernández (BsR Components)
UBR wGDP wSB
-4.2 0.8 -0.5

The numbers from Baseball Savant are especially damning for Hernández. His success rate on advance attempts is 85%, the lowest figure among qualified runners. He has cost his team more runs by getting thrown out than any other player in the game. His worst mistakes have come at second base; on five different occasions, he has been gunned down trying to stretch a single into a double. In his defense, he’s legged out his fair share of doubles, too, but a single failure is far more harmful than even two or three successful attempts:

The final two baserunners who caught my eye fall into a third category. Nathaniel Lowe and Max Kepler have sprint speeds in the palest pink on Baseball Savant. In other words, speed isn’t a selling point for either one of them, but still, they shouldn’t be getting into quite so much trouble on the basepaths:

The Average Runners
Player Sprint Speed Percentile BsR Rbaser BRR Baserunning (Savant)
Nathanial Lowe 51st -5.6 -3 -2.3 -3
Max Kepler 55th -4.4 -2 -0.8 -3
Rbaser via Baseball Reference, BRR via Baseball Prospectus, Sprint Speed and Baserunning via Baseball Savant

Lowe ranks as one of the five least-valuable runners in the league this year, with -5.6 BsR. On a per-game basis, Kepler has been just as bad, compiling -4.4 BsR in 27 fewer contests. To make matters worse, these two might actually be faster than their sprint speeds suggest, yet they’re still hemorrhaging runs on the bases:

The Average Runners (Home-to-First, 90-Foot Splits)
Player Sprint Speed Percentile HP to 1B Percentile 90-ft Split Percentile
Nathanial Lowe 51st 69th 59th
Max Kepler 55th 74th 76th
SOURCE: Baseball Savant

Neither Lowe nor Kepler has stolen a base this year, but the real problem lies in their UBR:

The Average Runners (BsR Components)
Player UBR wGDP wSB
Nathanial Lowe -4.2 -0.2 -1.2
Max Kepler -3.3 0 -1.1

More specifically, Lowe’s biggest shortcoming is that he doesn’t advance on hits. Baseball Prospectus has him at average or above average in every other baserunning category, but he ranks dead last in Hit Advancement Runs. The data from Baseball Reference backs this up; his XBT% ranks eighth-worst among qualified runners. He has scored from first base on a double only three times in 14 chances, which is half the league-average rate. Similarly, he has gone first-to-third on a single only four times in 26 chances; once again, that’s half the average rate. According to Baseball Savant, Lowe is tied for 16th in advancement opportunities, yet he has attempted to advance 5% less often than the average player. He’s holding himself back by literally holding himself back.

Kepler’s problems are more varied. His XBT% is below average, and his advancement success rate ranks 287th out of 298 qualified runners. However, he also hasn’t had many chances to advance. He ranks 172nd with only 75 advancement opportunities, per Baseball Savant. He has found himself on first base when a single was hit only 14 times, and he’s been on first for a double only twice. From 2020-22, Kepler racked up 8.1 BsR, 5 Rbaser, and 4.8 BRR. Considering his past success and above-average sprint speed, I’m inclined to believe he can turn things around with more opportunities (and with more time removed from the leg injuries that plagued him earlier this season). After all, we’re talking about the guy who pulled off this baserunning stunt and still legged out a double:

By and large, the best basketball players are tall, the best weightlifters are strong, and the best baserunners are fast. It’s just common sense. Still, being slow doesn’t have to be excuse for poor performance on the bases (just look at Freddie Freeman), nor it is the only reason a player might struggle on the basepaths. From slowpokes like Correa to speedsters like Duran (and all the Lowes and Keplers in between), some runners simply don’t make the most of their wheels.

All stats and rankings through August 30.





Leo is a writer for FanGraphs and MLB Trade Rumors as well as an editor for Just Baseball. His work has also been featured at Baseball Prospectus, Pitcher List, and SB Nation. You can follow him on Twitter @morgensternmlb.

36 Comments
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bri0hmember
8 months ago

Great article! I would be curious if Rosario’s UBR, RS%, and XBT% will all go up now that he is with the Dodgers and has (famously great) Dino Ebel coaching third base. It seems like it would be impossible to quantify, but I would be interested in knowing what impact certain third base coaches have on a runner’s XBT% specifically. Freddie Freeman has always been an efficient runner, but has really turned it up this year, coincidence he’s now settled in as a Dodger?

bosoxforlifemember
8 months ago
Reply to  bri0h

Your comment brings up a point that isn’t considered nearly as much as it should be and that is the importance and quality of the 3rd base coach. Since there is no alternate universe to rerun a play it is impossible to know whether the 3rd base coach made the right call or not but the coach who never has a runner thrown out stinks. In today’s game, with so many strikeouts, getting a man in from 3rd against Bautista, Clase or any top flight pitcher has a low percentage probability but I watch runner after runner being held up unless it is a virtual certainty that he can score easily. I only have my eyes to support my claim but Carlos Febles, Red Sox coach, appears to be among the most hesitant to take any risk at all. Is there a statistic available that offers the percentage of men thrown out at the plate?

Ostensibly Ridiculousmember
8 months ago
Reply to  bosoxforlife

Looking at FG’s team Base Running Runs above Average and comparing with team average sprint speed from Baseball Savant…

Cubs lead MLB in BsR but are only slightly above average in speed. Mets and Giants are both near the very bottom in speed but solidly above average in BsR.

Rangers are tied with Cubs in average sprint speed (slightly above average) but well below average in BsR.
Colorado is the worst base running team by far. They’re slow, but not slow enough to warrant a ridiculous 18 runs below average.

tiffanybee
8 months ago
Reply to  bosoxforlife

How can you say that? A 100% success rate can be reflective of extreme reluctance or extreme skill for a 3B coach.

What would be an acceptable success rate? 85%? 70%? Wouldn’t you think it might be context dependent?

maguromember
8 months ago
Reply to  tiffanybee

A third base coach with a 100% success rate is almost certainly leaving runs on the table. A runner rounding third with two outs, for instance, would only need a scoring probability a little over 25% to make going for it a good call.

tiffanybee
8 months ago
Reply to  maguro

Generally, what you say makes sense, if we don’t know who the next hitter is, or who’s pitching, or how many baserunners are also on, or what the score is. In any particular real situation, everybody knows all those things including the 3B coach.

I think it’s a bit more nuanced than to say the coach is a fool for sending a 20% chance or a coward by holding a 30% chance. I know that’s not what you said; just illustrating.