Measuring This Season’s Most (and Least) Consistent Hitters

There’s a question that gets asked all the time on baseball social media. The variations are endless, but essentially, it boils down to this: Would you rather have an ultra-consistent hitter in Player X, who you can count on for a daily hit, or an uneven hitter in Player Y, who oscillates between prime Barry Bonds and a benchwarmer?

Given specific numbers, you could work out whether Player X or Y is more valuable. But what if we assume they’re players of equal caliber? That’s where it gets tricky. Maybe I’m only seeing certain answers, but in such cases, it seems like people prefer the clockwork Player X. It makes sense: The prospect of guaranteed production is reassuring, as befits our risk-averse tendencies. I have a hunch that we generally overvalue consistency in baseball, but I’m not here to prove that. Instead, I wanted to find out which hitters have been steady at the plate this season, and which hitters have been mercurial.

Over on our Splits Leaderboards, you can break down hitters’ seasons into weekly chunks. They range from Isaac Paredes’ destruction of the league in mid-June (488 wRC+) to Travis Demeritte’s hit-less and walk-less stretch a month prior (-100 wRC+). From there, measuring the variance between those weeks is a fairly simple endeavor. I grouped the weeks by each player, then calculated the standard deviation in wRC+, which represents how spread apart a player’s weeks are from his overall production. The higher the standard deviation, the more variable he is; the lower the standard deviation, the more consistent.

As uncomplicated as that sounds, there are a few caveats. A week as defined by our leaderboards spans from Monday to Sunday, which is a bit arbitrary and might fail to capture the true ups-and-downs of certain hitters. Another thing to keep in mind is that in order to make sure each week contained a meaningfully large sample, I filtered out weeks with fewer than 20 plate appearances. This affects more hitters than you might think. Even the league’s best hitters occasionally fail to reach that threshold due to a combination of rest days, minor injures, or their team’s schedule. As such, the aggregate weeks aren’t exact representations of what hitters have accomplished this season. But they’re good enough approximations; Aaron Judge is still Aaron Judge, for example.

With all that in mind, it’s time for some fun. By standard deviation, here are the five most consistent hitters of 2022 (with a minimum of 200 total plate appearances):

Despite Patrick Wisdom’s whiff-tastic approach, he’s been oddly consistent throughout the season, with only two weeks spent below the 100 wRC+ mark. It also means he’s never been white-hot, but that’s why he claims the throne here. Wilmer Flores has been one of the Giants’ most reliable hitters, which is a compliment to the player but not so much to the team. Meanwhile, Alec Bohm and César Hernández are cases of being bad with regularity – ouch. The real star, however, is Pete Alonso, who basically hasn’t taken a week off all season; he’s great, and so are the Mets.

On the flip side, here are the five least consistent hitters of 2022, as determined by standard deviation (with the same plate appearance threshold as before):

Hey, the Fish Man is on top of yet another leaderboard! This one’s a bit unflattering, though. Yes, Mike Trout is on pace for another 7 WAR season, but along the way, he ran into the absolute worst slump of his career. And just recently against the Astros, he struck out nine times in a three-game series without recording a hit or a walk. There’s probably no predictive value in a hitter’s week-to-week inconsistencies, but nonetheless, Trout has often been either brilliant or practically unwatchable this season.

It’s been a similar case for J.D. Martinez, who once followed up a 273 wRC+ week (May 23 to 29) with a 4 wRC+ one (May 30 to June 5). Giancarlo Stanton went upstream instead, leaping from a -57 wRC+ to a 227 wRC+ back in late April; since then, he’s mostly settled in. Yordan Alvarez has been more up and down, but his highs are so darn high that they practically quash any small-size slump he runs into. The odd one out here is Owen Miller, who of the five hitters listed is the only one producing at a below-average clip. We’ll talk more about him later.

But what attributes of a hitter are associated with the existence or lack of consistency? You might think hitters with strikeout issues are more volatile than those with strong bat-to-ball skills. Indeed, before collecting the data, my mind instantly went to Javier Báez, who’s a swing-and-miss deity and one of the streakiest players I’ve ever seen. Báez didn’t crack the top 10 in standard deviation – he’s 14th, if you’re wondering – though that might be because his signature home run binges have been few and far between this season. What about the league as whole? From our sample, here’s the correlation between a hitter’s strikeout rate and standard deviation of wRC+:

Surprisingly, the correlation is nonexistent. Strikeout-prone hitters may look ugly when they slump, but it doesn’t necessarily mean they’re more likely to do so. In a sense, Báez is a viable major league hitter because he’s capable of transcendent streaks; without them, all the strikeouts would absolutely crater his numbers. Another (recent) baseball truism is that disciplined hitters remain consistent, but the correlation between walk rate and standard deviation is nonexistent, too. If anything, there’s a very slight positive relationship!

That fact provides a nice segue into the next graph, which shows that better hitters tend to have higher standard deviations:

This isn’t because a lack of consistency leads to good results, of course. But perhaps it challenges traditionally held notions of how All-Stars come to be. We might picture our favorite hitters exuding greatness through a steady stream of hits. In reality, it seems, the very best players are explained by their ability to string together incredible streaks of slugging that appear like blips on a patient’s heart monitor. They’re deviations from the norm, and at the same time, that norm is up there to begin with. Looking at the data, it occurred to me that the highest weekly wRC+ marks often belonged to top-tier hitters. Why is Mookie Betts awesome? Because he’s capable of putting up a 294 wRC+ across an entire week, that’s why.

Lesser hitters, on the other hand, usually lack the tools needed to forge a monster week – and if they succeed, they’re probably no longer considered lackluster anyways (see: Paredes, Isaac). There’s also a positive relationship between a hitter’s standard deviation of wRC+ and average wRC+ because worse hitters are consistently not good. Or I should say, they at least maintain a level of competency deemed appropriate for the major-league level. Once hitters slip below that demarcation, they’re either given less playing time, sent down, or released altogether. So there is a bit of survivorship bias baked into the data we’re seeing, as certain hitters who do fluctuate – between merely bad and cover-your-eyes bad, that is – don’t accumulate enough plate appearances to warrant inclusion.

Then again, it’s possible simple standard deviation isn’t the best method of quantifying consistency. Consider Owen Miller, who we saw earlier. The Guardians’ infielder wasn’t in the top five because of his tendency to shift back and forth. Rather, it was because a single week had an outsized influence on his standard deviation:

Miller had a whopping 330 wRC+ in his first full week of the season. But without it, he resembles a consistently decent contributor, and that isn’t what we’re looking for. In search of a more robust measure, I ended up using the median absolute deviation (MAD), which is the median of the absolute deviations from the data’s median. It’s still simple, but with the added bonus of a resilience against outliers. With a new process, here are the five most consistent hitters of 2022:

And here are the five least consistent hitters:

It’s hard to say for sure, but I do think this bunch passes the eye, smell, or whatever other sensory test you prefer with higher marks. For example, the most consistent list is now made up of hitters who bounce between the okay and good stratospheres rather than those who are predictably below-average. As for the least consistent list, Votto sticks out this time, but we’re not seeing a repeat of Miller here – this season, Votto started off cold, got hot, and is now trending back down. That’s not what we want as fans, but it is what we want for this article.

Ideally, there’s a method of measuring how often a player dips below and then soars above his baseline output; that might provide us with a more accurate assessment of which hitters are and are not consistent. But I haven’t figured it out, and for now, I’m content with what’s recorded here. Beyond the featured hitters, it’s good to know there’s an unexpected reason behind who tends to be consistent and why. That’s the value of putting assumptions to the test – even if it seems like a fruitless task, you never know what you might end up learning.

Statistics in this article are through the games of July 3.