Josh Naylor is slow. Not slow in the way that catchers are considered slow by default, or how some tall lanky guys seemingly can't get their legs moving, or even slow in the way that Kyle Schwarber is. Josh Naylor is third-percentile sprint speed slow. Josh Naylor is the 16th-slowest guy in baseball, and the third-slowest first baseman—he'll beat Triston Casas and Rowdy Tellez in a footrace, but if you put him against a fast shortstop like Trea Turner, he's never winning.
But if you're only counting stolen bases, it's a different story. Turner currently has 25 stolen bases this year, on pace for a very respectable 35-steal season. He has been caught stealing six times, for a roughly 80 percent success rate, which satisfies the heuristic—though it is only a heuristic—of the 70 percent breakeven point. Not shabby at all! Bobby Witt Jr. has 30 stolen bases on the season and has been caught stealing seven times, for a roughly 81 percent success rate. Again, that's about what you'd expect. Meanwhile, Naylor has 21 stolen bases on the season and has been caught stealing only twice, for an absurd 91 percent success rate. Those are Oneil Cruz numbers, with the caveat that Cruz has attempted to steal 15 more times than Naylor.
Even more absurdly, Naylor attempted only 13 steals in the 93 games he played with the Arizona Diamondbacks this season. Since being traded to the Mariners 12 games ago, someone has let him off the leash, and the results are frightening. Naylor has successfully stolen a base 10 times on 10 attempts. His previous career season-high in steals was 10; he has now accomplished that in 12 games. This rate is so unsustainable that it's not even worth calculating how many steals he'd end up to close the season if he continued stealing at this clip (68, if you truncate).
Naylor has no doubt benefited mightily from his opposition. Two nights ago, against the Chicago White Sox, Naylor stole two bases on top of hitting a two-run homer. Last night, also against the White Sox, Naylor once again stole two bases, on top of hitting a two-run homer. (The audience eagerly awaits the conclusion to the White Sox–Mariners series later this afternoon. It's only one of four games played today, so you may as well tune in.) The video section of the Statcast basestealing run value leaderboard unfortunately hasn't been updated since late July, perhaps because they don't want you to see Josh Naylor pulling off steals like this:
And this:
A few months ago, the Defector staff bandied about a theory that Kyle Schwarber, who always manages to steal a good few bases a season, was secretly a good baserunner. The theory went that Schwarber benefited from lax defense due to his reputation for speedlessness, and thus he could get good jumps and take more bases. Despite being slow, he had the cunning of a man who knew he couldn't get free bases on raw speed alone, and so could outperform his teammates who, while not necessarily the fastest, were still quicker than him, like Alec Bohm.
This is, according to Statcast, not true! Schwarber is worth negative-3 baserunning runs this season; Bohm is worth a mere negative-1. While humans only count what they see, and only factor in plays that occur, Statcast's baserunning statistics care about lost opportunity cost, and this is where slow players get hit. They don't go for as many extra bases as their faster peers would; even if they don't get thrown out, they get held up. The same applies for Naylor, who, in spite of his impressive basestealing, is also worth negative-1 baserunning runs.
But while the underestimation theory may not apply to extra base opportunities, it does hold up within the isolated environment of stolen bases. Naylor's average lead on all stolen base opportunities isn't particularly high. It's gone up significantly since he joined the Mariners—an average of 4.6 feet instead of 3.0 feet—which is high, but not obscenely so when compared to the rest of the field, which broadly falls within the 3.0 to 4.5 range. Oneil Cruz averages a 3.8-foot lead; Bobby Witt Jr. averages a 4.5-foot lead.
Where Naylor stands out is his average lead on his stolen base attempts. That is, when he goes for it, he starts further than the best stealers in baseball. Cruz averages an 8.0-foot lead on his stolen base attempts. Naylor's comparatively speedier teammate Randy Arozarena averages an impressive 11.7-foot lead. Meanwhile, Naylor is out here getting 15.7-foot leads on average for his stolen base attempts. (Schwarber, for those keeping track at home, gets 16.1-foot leads.) It's not hard to guess how Naylor accomplishes this. If a runner as fast as Cruz is on base, a defense is never allowing him to get a, say, 23-foot lead unless something goes very, very wrong. But there's no need to keep a close eye on someone as slow as Naylor, and it is this logic that has earned him about as many net bases via steals as Trea Turner—he's getting opportunities that fast guys would never have and taking full advantage of them.
Talk about cunning! Josh Naylor, who has the nefarious mien of a Disney villain, is pulling fairy-tale trickster maneuvers on the rest of the league, and I see no reason why anyone should get involved. You know you want to see Josh Naylor steal 68 bases this season. It's what we all deserve.
