If you’re a baseball lifer like me, you know that the genesis of Baseball Savant has really changed everything about the way we process the games we watch. 

Gone are the days where we must witness a line drive out and say, “Wow, that seemed like good contact,” because we instantly have the exit velocity and expected batting average to accompany it, so we can properly tell if a hitter got hosed. And if you extrapolate that data from one batted ball out to an entire season, we’re able to start drawing some real conclusions.

We also no longer look at just a player’s raw statistics to determine whether we think he’ll be successful for the rest of the season. Thanks to Statcast data, we can see how often a hitter barrels up the ball, or how often a pitcher keeps the hitters they face from doing so. We can look at chase rates and swing and miss rates to see whether a player is winning the cat and mouse game during at-bats. And perhaps most fun of all, we get to determine who the unluckiest players in Major League Baseball are.

Now, don’t get me wrong. I do think there are limits to expected stats–whether it’s batting average, wOBA, ERA or slugging percentage. The reality is that there are too many variables for Statcast to measure and a hitter’s tendencies to hit the ball to the same spots or a pitcher’s inability to recover from unlucky outcomes early in innings might go undetected in the calculations. It's not a perfect science by any means.

But I also think there’s a ton we can glean from expected stats–and even if we can’t say everything with 100% certainty, it’s fascinating as a thought exercise to look at massive differentials like the ones I’ve selected and attempt to draw some conclusions. Are these players suffering from disproportionately bad luck? And what other potential causes can we see from other Statcast measurements? Today, we’re putting that all to the test. Get ready to nerd out, comrades.

Hitters (expected stats page here):

Ryan Mountcastle - 1B/OF, BAL

The loyalest of loyal readers will recall that I made a declarative statement about Mountcastle being one of the unluckiest hitters in existence back in the very first edition of the Picks to Click. It’s remained true in 2023 and of all the case studies, this one most makes me question whether expected stats do in fact regress to the mean over long enough periods of time. 

Firstly, Mountcastle is probably the number one person in the entire world who should be pissed off about the left field wall at Camden Yards being pushed back. It went from being one of the four or five most forgiving left fields in MLB to by far the most punishing. And as a power-oriented hitter with a pull swing, Mountcastle hits some absolute rockets out to left that should be rewarded… and yet, his ballpark architects have done him dirty.

Regardless of the cause, the numbers are striking. Mountcastle’s losing 37 points off his expected batting average (.268 vs .231 actual). His xwOBA is 57 points higher than his wOBA (.356 vs. .297), the fifth-largest differential in MLB. And he’s somehow 108 points off his expected slugging percentage (.537 vs. .429 actual), which is the third-largest differential of anyone. And by the way, that .537 xSLG is the 18th-highest in all of baseball, right behind two guys named Goldschmidt and Ohtani.

So what should be done here? Well for fastest results, Mountcastle should likely either A) learn how to hit lefty, B) burrow underground like Bugs Bunny and move the fence in when no one’s looking or C) walk into Mike Elias’ office and demand a trade to Cincinnati.

But for longer-lasting benefits, Mountcastle should also definitely stop chasing awful pitches. He’s currently in the 2nd percentile in chase rate and as a result, in the 9th percentile in walk rate. It’s great to make consistent loud contact, but in today’s game, discipline is ever more important.

Unlucky meter: 9/10

Michael Harris II - OF, ATL

Wednesday’s big game, punctuated by a go-ahead homer to defeat the hated Mets, was a step in the right direction after a brutally discouraging start to the Rookie of the Year’s sophomore campaign. But according to Savant, that start has been unlucky in addition to being subpar.

.310 is by no means a good wOBA, and that’s what Savant says Harris should expect to have at the moment. But it’s also night and day difference from .250, which is a borderline indicator that someone should be out of the league. And that’s what Harris is still rocking more than a week into June.

It makes sense–Harris is still making some loud contact. He’s in the 75th percentile in hard hit rate and the 93rd in max exit velocity. But he’s also in the 14th percentile in chase rate and 23rd in whiff rate. And I believe I’ve pinned down one pitch in particular that’s causing the sophomore slump.

Last season, Harris hit .274 with a .324 slugging percentage against changeups, good for a run value of one (193-pitch samples size). This season, he’s hitting .059, slugging .059 and whiffing 45.9% of the time, up over 18% from last year. That’s produced a run value of -5, in just a 58-pitch sample. Yes, Harris has been unlucky at times, but this is a real hole in his approach, one that will only be exploited more if he can’t adjust very, very soon.

Unlucky meter: 5/10

Keibert Ruiz - C, WSH

I’m absolutely bullish on Ruiz. He’s a 24-year-old switch-hitting catcher with a .374 xwOBA. Adley Rutschman, for context, is a 25-year-old switch-hitting catcher with a .353 xwOBA. Yes, it is likely irresponsible to draw such a comparison without any other qualifiers. But it should at least tell you that there’s some special potential there. At the catching position, good hitting, let alone elite, is extremely rare and a huge bonus to a team’s prospects of contention.

Now, the dark cloud. Ruiz’s actual wOBA is .303. The 71-point difference is second in baseball to only Dodgers shortstop Miguel Rojas, a fascinating case study that will have to wait for another day. And unlike most of the other hitters with large differentials, Ruiz isn’t hitting the ball very hard. Statcast thinks he should be performing better because he has bat-to-ball skills that can only be described as otherworldly.

In an era where most hitters are piling up the strikeouts, Ruiz is allergic to them. He’s only K’ed 16 times all season, which puts him in the literal 100th percentile of all hitters. The only qualified hitter with fewer strikeouts is the man currently chasing .400, Luis Arraez. That should tell you just about all you need to know about how much contact Ruiz makes.

Now, Ruiz is not Arraez–all you need to see to confirm that is his .233 batting average, juuuuust a bit south of .400. But they’re both hitters who don’t hit the ball particularly hard in a raw exit velocity sense–Arraez has just figured out how to channel that better. Arraez is hitting .417 on balls in play and Ruiz is at .222. He’s got to learn to lean into the elite tool he has and start spraying the ball all over the yard–and at such a young age still, I truly believe he can.

Unlucky meter: 7/10

Anthony Rendon - 3B, LAA

Once a World Series hero in D.C., Rendon’s Angels tenure has thus far been marked by injury (he’s only three games back after missing three weeks with a bad hamstring) and inconsistency. And between the injuries and the dip in slugging percentage, you’d think Rendon was actually much older than 33. He’s still got plenty of years left if he can ever manage to stay on the field!

That’s why I read into the disparity between Rendon’s expected stats this season and his raw numbers as an encouraging sign. This is a proven veteran with a disciplined approach–he’s in the 98th percentile in chase rate! He’s also got a .394 xWOBA, which ranks right between Bo Bichette and Mookie Betts for 17th in MLB.

Yes, the power is unlikely to ever fully return to 2019 levels, when he socked 34 dingers and led MLB with 126 ribeyes. But Statcast thinks he should be slugging .437, which would be more than enough to make him a standout player with his high batting average. In reality, though, he’s slugging .349. If track record over long stretches is any indication, there should be some positive regression in store for a hopefully healthy Rendon

(Immediately searches around for every piece of wood in the house to knock on vigorously.)

Unlucky meter: 7/10

Bobby Witt Jr. - SS, KC

Look, it’s by no means revolutionary to say one still expects big things from a former #2 overall pick who turns 23 this upcoming Wednesday (happy early birthday, Bobby!). But Witt has a .517 xSLG compared to a .417 SLG. That translates to a 56-point gap in actual vs. expected wOBA, sixth in all of baseball.

And we actually can’t blame the park like we can for a guy like Mountcastle. The 2023 right handed park factor for Camden Yards is 93, sixth-toughest in all of MLB. Kauffman Stadium’s is 105, seventh-easiest. It’s playing as the fourth-best triples park as well, which should play right into Witt’s speedy toolkit. 

No, it’s a more approached-base critique we need to apply to Witt, which begins with the results he’s seeing on specific pitch types. He has a staggering -10 run value on four-seam fastballs, which you’d typically expect to be a young player’s bread and butter. And against the pitch sweeping the nation, the ever-vaunted sweeper, Witt is batting .083 with a 30.8% strikeout rate. It’s almost a pick-your-poison situation.

Once again, the good news is that Witt is still so young. He’s bound to see some positive regression with how hard he hits the ball (85th percentile in barrel rate). And as a speedster (100th percentile sprint speed) and defensive vacuum (97th percentile in outs above average), he provides lots of value beyond his bat. But… you don’t draft someone second overall for speed and defense. He’s got a lot of maturing still to do at the plate.

Unlucky meter: 6/10

Pitchers (expected stats page here):

Tanner Houck - RHP, BOS

Now, I’m by no means the first person to point this out, but for starters, Houck truly looks like a righty Chris Sale. The mechanical similarity is uncanny. Ironically, Sale is one of the unfortunate pitchers to join Houck in the top ten of xERA - ERA differential. But while Sale is tenth, Houck is all the way up in second place among pitchers with a minimum 150 batted ball outcomes. His 5.46 ERA is insulting compared to the 3.85 Statcast believes it should be.

It was well-documented that Houck was dominating hitters early in the season the first time they hit against him, then struggling progressively more the second and third times through the order, which led many to believe he should be moved back to the bullpen. That still could happen at some point, though Houck has struggled the first time through the order in his last two starts. But let us treat Houck as a fixture in the rotation for the time being, because frankly, the Red Sox have few options.

The biggest difference between starter Houck and bullpen Houck is that starter Houck has a hittable slider. In 2022, when Houck started in just four of his 32 appearances, hitters had a .152  average against the slider. This season it’s .213, which is by no means a dealbreaker, but it’s no longer a stone cold putaway pitch. The spin rates and whiff rates are nearly identical as well, which leads one to believe it’s more of a location issue.

The other confounding variable is the Red Sox’ awful defense, which Houck sadly cannot exercise any control over whatsoever. The stats are bad but the eye test is worse. And the eye test, conversely, tells you Houck should be a good major league pitcher. But even if his luck turns, that question is still unsettled.

Unlucky meter: 7/10

Nestor Cortes - LHP, NYY

The laws of internet engagement dictate that if we discuss a Red Sox player, we must also talk about a Yankee. So why not devote this space to the most surprising Yankee success story from a year ago, and who might now be their biggest disappointment?

Sadly, Cortes has been placed on the 15-day IL with a strained rotator cuff, which will make all this talk irrelevant until he returns to the field. It's also sad because he won't be there to face the music for his comment about the Red Sox earlier this week (see embedded tweet). But he’s been both bad and unlucky this season, which makes him perfect for this list. With a 5.16 ERA vs. a 3.75 xERA, there’s a mixture of underperformance (compared to last season especially) and batted ball misfortune.

It’s really a combination of things and not one particular culprit I can point to as to why Cortes is struggling. The home runs are slightly up. So are the walks. The strikeouts are slightly down. The BABIP is noticeably up, which is mostly not his fault. 

My primary cause for concern, then, is that Cortes’ deception is no longer working as well as it did a year ago when he finished eighth in the Cy Young voting. As a soft thrower (by today’s standards, at least), Cortes relies on keeping hitters guessing and off balance. And when he comes back from injury, he’s got to find some new ways to do that. Of course, there are still unlimited wacky windup variations he’s yet to explore!

Unlucky meter: 6/10

Logan Gilbert - RHP, SEA

Gilbert is being asked to carry more of the freight in the Seattle rotation this season with Robbie Ray, who pitched 189 innings last season, shelved for the year. And he’s proving himself a very capable workhorse. But Savant data tells us he could be closer to an ace.

Gilbert has a 2.99 xERA and a 3.80 ERA. It’s cheating a little bit, because his xERA is so close to 3, but of everyone whose ERA is over 3, Gilbert has the lowest xERA. Got that straight? That sentence didn’t confuse you too much? Excellent, let us proceed.

At 6’6, Gilbert gets silly amounts of extension towards the plate, which makes his 75th percentile velocity look a lot faster. But his fastball has extremely low spin (hovering around 2,000 RPM) and as a result, hitters fare reasonably well against it. And this season, he’s allowing a .350 wOBA on fastballs, well worse than a top end starter needs that metric to be.

So even if it’s too late for Gilbert to start spinning his fastball more (unless he invents a new kind of sticky stuff that can’t be detected by overzealous umpire crews), he’s got to find a way to keep hitters from populating the bases against his fastballs. With his strikeout rate up 5.5% from a season ago, we can trust that the rest of his arsenal is good enough to make him a fixture at the top of the Seattle rotation.

Unlucky meter: 7/10

Aaron Nola/Zack Wheeler (RHPs, PHI)

For our last two entrants, why not group a pair of teammates together? Because holy cow, are they both eerily similar in the world of bad luck this season. 

Yes, the two have a lot in common besides both almost no-hitting the Detroit Tigers this week. At the time of writing, Wheeler’s stats have yet to update after his stellar outing Thursday night. But as it stood before Wheeler took the hill, the Philly aces’ wOBA, xWOBA, ERA and xERA were all within 13 percentage points of each other, and in the case of ERA, they ranked 15th and 16th respectively in differential in comparison to xERA.

Now, let us separate the two for a moment, because after all, they are different people. 

Wheeler is suffering from increased slugging percentages on both his four-seamer and sinker. The sinker is particularly concerning, because he’s throwing it more than a year ago with worse results. But overall, he’s still having a solid season and 7.1 innings without an earned run goes a long way towards pushing the overall numbers back into the “really good pitcher” category. His ERA dropped from 4.33 to 3.91.

Nola is a stranger case, because his BABIP is actually down from a year ago. He’s never thrown gas, but his velo is still a bit down. And it’s not as though he’s getting outright hammered. He’s lost his command a little. His home run rate is up from 0.8 to 1.4 per nine innings and his walk rate is up from 1.3, which led the NL last year, to 2.3.

All of this is a long-winded way of saying that I do think both of these pitchers can still be very good. But the Phillies are built on the premise that they can compete with the very best in the game. And the question of whether or not they can do that is best left for another day. Preferably, for our purposes, a day where they don’t face the Tigers’ cupcake lineup.

Unlucky meter: Wheeler 8/10, Nola 7/10

***

BONUS LIST: People who I also could have written about, but didn’t have the space…

Miguel Rojas (.225 wOBA, .308 xWOBA)

Edward Olivares (.309 wOBA, .360 xWOBA)

Trent Grisham (.348 SLG, .447 xSLG)

Sandy Alcántara (5.07 ERA, 4.02 xERA)

Matthew Boyd (5.57 ERA, 4.02 xERA)

Paul Sewald (2.84 ERA, 1.68 xERA)