Calling a rough second season a “sophomore slump” has been ubiquitous in the game of baseball at least for as long as I’ve been watching it.
In traditional analysis, it’s been used to temper expectations after a player sets fire to the game in their first season — sometimes not even rooted in facts but rather just a reckoning to people having seen it time and again.
But the reality is that the game is a cruel mistress. Opponents adjust. Hitting and pitching at the game’s highest level is hard.
Sometimes players have a hot stretch buoyed by luck or some such fortunate sequencing, resulting in their first season being the best of their career.
- Pat Listach – The 1993 Rookie of the Year was worth 4.5 bWAR in his rookie season with the Milwaukee Brewers. His bWAR at the end of his career? 4.4. Yikes.
- Bob Hamelin – The 1994 Rookie of the Year who hit .282/.388/.599 in 101 games, then hit .168/.278/.313 the next season and was out of baseball within four years.
- Angel Berroa – The 2003 Rookie of the Year who hit .287/.338/.451 in 158 games, then went on to hit just .249/.291/.353.
There’ve even been some notorious post-rookie dropoffs for the Minnesota Twins, as well. Perhaps the most notable recent one was Danny Santana, who revived his career in 2019 with the Texas Rangers.
Santana, who turns 30 in November, hit .319/.353/.472 for the Twins in 2014. He followed that up with a .215/.241/.291 line in 91 games the next season, and by 2017 found himself on a one-way train to Atlanta.
Santana isn’t so much a cautionary tale as he is proof that a career doesn’t have to be defined by a rookie year, a cliff dive after it or anything in the interim. Sure, he benefitted from the juiced ball in 2019, but a 111 wRC+ is nearly double the mark he put up in a 15-game cup of coffee with the Braves in 2018 (58).
So what does this have to do with the Twins?
Let’s talk about Luis Arraez.
Arraez wasn’t even supposed to be in the big leagues in 2019.
He missed almost all of 2017 with a torn ACL, then came back to Fort Myers and hit .320/.373/.421 in 60 games in 2018 before making the jump to Double-A (.298/.345/.365). Arraez opened 2019 with Pensacola and raked to the tune of a .342/.415/.397 line before jumping to Rochester to hit .348/.397/.409 in 16 games.
Then, it was time for the big show.
To say he wasn’t supposed to be in the big leagues last year isn’t meant to be any sort of dig. He’d only played 48 games above High-A. The Twins had signed Jonathan Schoop to keep the keystone warm for someone — maybe Arraez, Nick Gordon, Royce Lewis or even Jorge Polanco.
It wasn’t exactly a Wally Pipp situation, but Arraez took the job and ran with it. Arraez’s OPS didn’t spend consecutive days under 1.000 until his 26th and 27 MLB games, and it took 42 games for it to dip under .900.
Where that’s truly impressive is that it was largely batting-average driven. It wasn’t until his 63rd MLB game that his average dropped under .340. Then it jumped back up over .350 for games 83 and 84 before settling at .334.
After 60 MLB games, Arraez was hitting .346. Incidentally, that was the best 60-game stretch of his entire season — and he was still 50-plus points away from immortality.
But in a short season, who really knows?
But that cuts both ways. What if Arraez struggles? Is that possible?
Let’s look at a few ways it is.
First of all, Arraez doesn’t hit the ball very hard. There were 225 hitters in MLB last year with at least 250 batted-ball events (BBE). Arraez ranked 183rd among those with a average exit velocity of 86.9 mph. That was the lowest of any Twin meeting that threshold.
By hard-hit rate — balls measured 95 mph or higher — Arraez ranked 217th with just 22.1 percent meeting that level. The next-lowest Twin was Polanco at 33.0 percent (179th).
Then, we move onto barrels. Barrels signify a certain hit type that leads to at least a .500 batting average and 1.500 slugging percentage in the Statcast era. It’s a bit of mumbo-jumbo, but here’s a primer on it.
The short answer is this: hitters like Nelson Cruz (first in Barrels per BBE percent) and Josh Donaldson (seventh) are near the top of this list because they barrel up the ball frequently.
Cruz’s rate per batted-ball event was 19.9 percent, and per plate appearance was 12.5 percent. For Donaldson, 15.7 and 9.4 percent, respectively.
Arraez, on the other hand, ranked 204th in Barrels per BBE at 2.7 percent, and 202nd in Barrels per PA at 2.2 percent.
In other words, this is more data suggesting Arraez doesn’t exactly crush the baseball. Fangraphs paints a slightly rosier picture with Arraez 211th out of 273 hitters last season (min. 300 PA) with a hard-contact percentage of 34.7 percent.
Again, it’s still not a rosy picture.
A hitter cut from Arraez’s mold typically does well to keep the ball out of the air — at least in terms of fly balls — based on exit velocity, and he makes that trade off well. The MLB average fly-ball rate for a hitter last year was 35.7 percent, while Arraez was at 29.1 percent while funneling most of it to line drives (29.4 percent vs. a league-average mark of 21.4 percent).
So when he hit it hard it was frequently a line drive, which is a good combination — obviously.
But a .355 BABIP? That’s awfully hard to sustain, isn’t it? Well…not necessarily. Arraez has been in that .350-.375 range throughout his minor-league career. Nine qualified hitters posted a BABIP over .350 last year — one of which was Santana and another was Cruz.
It can be done, but it usually takes a lot of luck or in the case of Christian Yelich (.355) pretty much just being a monster with the bat.
Players typically fall within a range of .290-.310 — some people prefer .280-.320 — but the MLB average last season was .298. Now it’s not a one-size-fits-all proposition because there are different strokes for different folks.
A player who sprays line drives is naturally going to have a higher BABIP than others.
xBABIP accounts for all of this and puts it into a tidy package. It takes a player’s batted-ball mix and computes what his BABIP should have normalized to. As noted before, Arraez posted a BABIP of .355 against an xBABIP of…..just .314.
Only one player with at least 200 plate appearances had a wider negative margin last season — San Diego’s Fernando Tatis Jr. (-.069).
The primary culprit for Arraez? Ground balls.
The MLB-average BABIP on grounders last year was .238 — while Arraez checked in at .312.
And that’s where it’s kind of difficult to forecast where to go from here. Switching up a batted-ball mix to hitting more balls in the air is, in general, the way to go for more extra-base hits, but as noted before Arraez doesn’t hit the ball particularly hard in general. He ranked 144th on the Statcast leaderboard (out of 225) in terms of average groundball exit velocity, and 205th in line drive/fly ball velocity.
He ran up his luck hitting the ball on the ground — not particularly forcefully, either — but when he hit the ball in the air, things really went even worse.
That lines up when comparing his fly-ball BABIP (.055) with the MLB average (.096) as well.
None of this is to say it’s a smoking gun that Arraez won’t continue to work his mojo on opposing pitchers but that the picture maybe isn’t as rosy as some have laid it out to be. His .104 isolated power was his highest since Low-A ball in 2016, too.
Any sort of regression to that would also, of course, hamper his overall line.
As a result, projection systems are a bit tepid on Arraez. He slashed .334/.399/.439 last season for a 125 wRC+ and .360 wOBA. Every projection system housed at Fangraphs has him pegged for a .420 slugging percentage or lower despite each of them having him hitting within three points one way or the other from a .310 batting average.
Oh, and speaking of wOBA — Arraez’s xwOBA was .336 last season, again suggesting he outperformed that mark by nearly 25 points.
That xBABIP of .314 keeps bringing me back to his first 48 games at Double-A back in 2018. That year, he had a BABIP of .315 and slashed .298/.345/.365. He walked a little less (6.7 percent) and struck out a little more (8.2 percent) than he did in the big leagues last season (9.8 percent and 7.9 percent, respectively), but that came out to a 103 wRC+.
Now, that was a .325 wOBA, so we could adjust up a bit. But if he hits something like that again, are fans going to be happy with it?
All I’m saying is it’s a really difficult tightrope to walk if a player has to hit .300 in order to be at least league average offensively. Again, at Double-A the first time around he hit .298 with a 103 wRC+. That, with questionable defense at second base, is not going to hold off the organization’s top prospect very long.
But even if Arraez struggles in 2020, it is after all just 60 games. When I started my wheels turning on this idea, it was back in the spring when 162 games were still on the table. And not only that, but a full minor-league season too.
So even if Arraez struggles, it’s not as though the prospects behind him will have had that time to creep up on him.
But if the Twins do deem Lewis ready to take over some position in the infield full-time in the next year or so, what does that mean for Arraez?
The Twins did try him a bit at third base (17 games) and left field (21) last season, with UZR/150 giving him fairly positive grades in obviously small samples. Could he reprise a quasi-Marwin Gonzalez role?
Keep in mind that both Marwin and Ehire Adrianza are eligible for free agency after 2020.
Maybe Luis as a super utility type in the future isn’t such a bad idea after all.
Thanks to Jeremy Frank and Baseball Savant for research assistance.