MLB's Top Candidates for Positive and Negative Regression at Quarter Mark

With the Major League Baseball regular season nearly six weeks old, there are a few statistical anomalies that appear to be unsustainable.

Justin Verlander and Michael Wacha cannot possibly maintain their historically great marks in batting average against and baserunners stranded, right? Just like Marcus Semien can't possibly go straight from a 45-home run season to a great big doughnut in that category?

Regression to the mean is coming.

Using a variety of metrics like BABIP, xFIP and SIERA to compare a player's production to both the current league averages and his previous career marks, we've pinpointed eight players who appear destined to get either substantially better or worse over the rest of the season—two pitchers and two batters in each direction. We'll oscillate between expected positive and negative regression.

To wrap things up, we'll also highlight the one team most likely to start trending in each direction.

Unless otherwise noted, statistics are current through the start of play on Monday, May 16.

2022 Stats: .157/.216/.213, 0 HR

2019-21 Stats: .268/.346/.509, 37 HR per 162 games

Before we begin, let's throw out a big disclaimer that will apply to all of our choices for positive regression: We have no way of knowing if these guys are quietly battling through some sort of injury/affliction. Case in point, we harped on Eddie Rosario's brutal start to the season for Atlanta only to find out he was dealing with eye swelling that necessitated surgery.

In other words, we're assuming that bad luck will turn around, but we acknowledge that these disappointing starts might be more than just poor luck.

Having said that, Marcus Semien is not hitting the ball like he used to.

Per FanGraphs, the exit velocity on Semien's batted balls is a full five miles per hour below what it was last season, falling from a career high of 89.7 to a career-worst 84.7. His line-drive rate (14.4 percent) is much worse than his career average (20.7), as is his soft-hit percentage (25.0 percent this year; 16.8 percent career).

Because of that, his batting average on balls in play (BABIP) is dreadfully low (.192), both by his career standards (.288) and compared to the 2022 league average (.284).

But he is at least putting balls in play. He's striking out in 18.0 percent of plate appearances after back-to-back seasons above 20 percent. He just seems to be pressing, seeing fewer pitches per plate appearance (3.65) than he typically does (4.04) and not capitalizing on the fastballs that he mashed with regularity in both 2019 and 2021.

Sooner or later, he's going to get off the schneid and finally hit his first home run in a Rangers uniform, and I suspect that will open the floodgates for a hot streak. One simply doesn't finish top-three in the MVP vote in two out of three seasons and suddenly forget how to hit a baseball.

2022 Stats: 1.38 ERA, 0.68 WHIP, 8.1 K/9

2019-21 Stats: 2.59 ERA, 0.80 WHIP, 12.1 K/9

It is wild that Justin Verlander is pitching this well at 39 years old, fresh off a Tommy John surgery that limited him to just one appearance over the past two seasons. But, to be clear, this selection has nothing to do with Father Time and everything to do with unsustainable metrics.

For starters, there's the .168 BABIP. In the past half century, no qualified starter has finished a season with a BABIP below .207—though Verlander did have a sensational .218 mark while winning the 2019 AL Cy Young.

Not only has Verlander been fortunate in that regard, but he has also been especially good/lucky when it comes to stranding runners. He currently has a left-on-base percentage of 94.7, which again would be the best in recent history by a wide margin. Shane Bieber's 91.1 mark in 2020 was the best of the past 50 years; Robbie Ray's 90.1 mark last year was the best among seasons with more than 60 games played.

And let's be sure to point out that he's hitting these unsustainable marks with a drastically lower strikeout rate than usual, which means he has been historically lucky on balls in play while also allowing more balls to be put in play. So, when the worm turns and balls in play start landing for hits, things could snowball.

That said, Verlander does have an xFIP of 3.36 and a SIERA of 3.27. Those numbers are nearly 2.00 higher than his ERA, which is the type of gap between actual and expected that screams "beware the impending regression." But even if his ERA did balloon to something in the 3.30 range, that would still be one heck of a season for a pitcher who turns 40 in February.

2022 Stats: 9.85 ERA, 1.74 WHIP, 9.9 K/9

2019-21 Stats: 3.76 ERA, 1.16 WHIP, 7.5 K/9

Can't get much worse than a 9.85 ERA, right?

Well, the metrics suggest things should get much, much better for Aaron Civale, who has been about as unfortunate as Justin Verlander has been fortunate.

Civale had a BABIP against of .249 last year and .250 in 2019, but his current mark of .382 ranks second-to-last among pitchers who have logged at least 20 innings of work. In that same group of pitchers, Civale also ranks second-to-last in ground-ball percentage (24.7) and last in left-on-base percentage (44.0).

In each of the past three seasons, he had a ground-ball percentage north of 40 and a left-on-base percentage of better than 72. So just like BABIP, not only are those numbers atrocious compared to current league averages, but they're also bad compared to what Civale has previously accomplished.

Just getting out of the first inning unscathed has been an arduous task for Civale, who has allowed multiple first-inning runs in each of his past four starts. He has also allowed five first-inning home runs during that stretch.

That horrid luck should improve, though, as he has an xFIP of 4.58 and a SIERA of 3.99, thanks to a solid K rate and a respectable K/BB ratio (3.4).

However, his velocities are concerning. Per FanGraphs, Civale is sitting at 90.5 MPH on his fastball, 86.3 on his cutter and 80.5 on his slider, each of which is more than a full mile per hour below his previous career low. That's something to monitor the next time he takes the mound, which will likely be against Detroit on Friday. If he can't stifle that anemic lineup, a "get right" trip to the minors could follow.

2022 Stats: .255/.350/.402, 2 HR

2019-21 Stats: .260/.344/.453, 20 HR per 162 games

The troubling thing about Chris Taylor standing out as a negative-regression candidate is he isn't even having a great season. In fact, his full triple-slash line is a bit lower than what averaged over the past three years.

However, when a player's BABIP (.400) is 145 points higher than his batting average (.255), that's a gigantic red flag.

Taylor does typically have a higher BABIP than most, with a .347 mark from 2017-21 that ranked eighth among qualified hitters. But .400 is all but guaranteed to decline.

There are two other concerning numbers in his stat sheet, the first of which is the 35.0 strikeout percentage.

Taylor has always been a bit high in that category and even "led" the National League with 178 whiffs in 2018, but he is swinging and missing at an alarming rate, particularly at balls not in the strike zone. Per FanGraphs, Taylor has a career O-Contact% (making contact when swinging at pitches outside the zone) of 50.1 and has yet to finish a season below 45.5. But he is currently at 32.9 and is showing no signs of improving.

The other concerning number is the 50.0 pull percentage. Taylor has always been a spray hitter. In 2019, he pulled 34.9 percent of balls in play, went up the middle on 32.9 percent and went opposite field on 32.2 percent. For his career, he's at roughly 38, 34 and 28 percent, respectively. It has long been anyone's guess where he would hit it, which is a big reason why his BABIP was so solid.

While he's still a far cry from a dead-pull hitter, defenses are going to start leaning in that direction if he keeps pulling the ball, which would bring his BABIP back to earth—and his average down to or below the Mendoza Line—in a hurry.

2022 Stats: .183/.213/.252, 2 HR, 5 SB

2019-21 Stats: .289/.331/.431, 15 HR and 30 SB per 162 games

Because of his speed, Whit Merrifield typically boasts an above-average BABIP. In each of 2016, 2018 and 2019, it was at least .350. And aside from a career low of .295 during the pandemic-shortened 2020 campaign, his worst full-season mark to date was a .308 BABIP in 2017.

As of Monday morning, though, his 2022 BABIP was at a shockingly low mark of .193.

To that end, Merrifield typically does a fair amount of damage on infield hits. He had at least 20 in each of 2017, 2019 and 2021. However, he has only one infield hit thus far this season.

It's not like the 33-year-old is abruptly losing his speed. Even with the woeful on-base percentage, Merrifield is on pace to steal around 25 bags. He still has more than enough speed to leg out infield hits if he could just quit hitting the ball directly at fielders.

And he has actually already begun turning the corner in that regard. Of his 24 hits on the season, 10 have come in the past week, as he finally started finding holes with his ground balls and soft liners against the Rangers and Rockies. Both of his home runs also occurred in the past seven days.

But there's still plenty more positive regression to be found here. Now that Merrifield is finally in a groove, he should stay hot for a while.

2022 Stats: 1.38 ERA, 0.92 WHIP, 6.6 K/9

2019-21 Stats: 5.11 ERA, 1.45 WHIP, 8.3 K/9

Michael Wacha emerging as a candidate for the All-Star Game has been a most unexpected development.

He made just three quality starts in the entire 2021 season, each separated by at least seven weeks and each lasting exactly the minimum of 6.0 innings. He made no such starts in 2020. And yet, the 30-year-old right-hander has been one of the few things about Boston's season that hasn't been terrible. (Or, at least he was prior to landing on the IL with a rib cage injury, though he should be back soon.)

Wacha has allowed just 13 hits in 26.0 innings of work. That 4.5 hits per 9IP rate would put him behind only Justin Verlander (4.3) if he had enough innings to qualify. He has compiled those numbers mostly against potential playoff teams, shutting down each of the Blue Jays, Rays, Angels and Twins.

But does anyone really believe that Wacha—who allowed 10.1 hits per 9IP over the past three seasons—is suddenly one of the most unhittable pitchers in baseball?

At least with Verlander's previously noted unsustainable metrics, we're talking about a two-time Cy Young winner and a probable Hall of Famer. If anyone can defy the odds, it's him.

With Wacha, the .162 BABIP, 94.3 LOB%, career-worst K rate (6.6 per 9 IP) and career-best HR rate (0.7 per 9 IP) read like a volatile cocktail. He also has both an xFIP (4.23) and SIERA (4.59) roughly three runs higher than his ERA, which is an implosion waiting to happen.

2022 Stats: 5.35 ERA, 1.37 WHIP, 11.5 K/9

2019-21 Stats: 3.00 ERA, 1.03 WHIP, 10.7 K/9

Among the 63 qualified pitchers from 2019-21, Brandon Woodruff ranked seventh in ERA and 11th in FanGraphs WAR (10.1). He was an All-Star in both 2019 and 2021, and he surely would have been if there had been an All-Star Game in 2020.

But he has been hit or miss thus far in 2022, saddled with a surprisingly high ERA since allowing seven earned runs in 3.2 innings in his season debut.

What's most astounding about Woodruff's slow start is the quality of opponents he has faced. Through seven starts, he has already drawn Pittsburgh and Cincinnati twice, plus one game each against the Cubs, Marlins and Cardinals. Of the bunch, only the Cardinals should have given him any trouble, but he threw five scoreless innings against them.

His swing-and-miss stuff is still there. Woodruff has logged at least six strikeouts in each of his past five starts, averaging 14.0 K/9 during that stretch. And while his walk rate (3.2 per 9IP) is a bit higher than usual, it's not like he has been handing out free passes left and right.

He's mostly just dealing with some rough luck and the occasional inning that gets out of hand.

Woodruff's current ERA is a bit ugly, but he has an xFIP of 3.37 and a SIERA of 3.15, which suggest he should be faring about as well as he did the past three seasons.

2022 Stats: .292/.366/.371, 2 HR

2019-21 Stats: .249/.377/.438, 24 HR per 162 games

New York's Mark Canha and Jeff McNeil each already have seven infield hits this season. That's a lot even for fast runners like Randy Arozarena, Julio Rodriguez or Myles Straw, each of whom has at least half a dozen infield singles on the year. But McNeil and Canha have a combined 45 career stolen bases and just one between them this season.

Not exactly your prime suspects for beating out ground balls on the regular, but that has been a huge part of their early success.

At least McNeil's BABIP (.343) is well in line with his career norm (.325). Even if and when his luck on infield hits wanes, we don't expect his numbers to plummet too much.

Canha, on the other hand, could be headed for quite the rough stretch. Both his batting average and BABIP (.364) are much higher than his career norms, even though both his soft-hit percentage (25.0) and ground-ball percentage (44.1) are also higher than in any previous season.

It's possible that Canha's regression will actually be positive in the form of starting to hit the ball as hard as he normally does. Per Statcast, his average exit velocity is way down, as he has barreled just 2.9 percent of batted balls after four consecutive years above seven percent. But given the way he's hitting the ball thus far, there's no way his batting average should be anywhere close to .300.

The Marlins should be flirting with a playoff spot, but they are instead tied for the fourth-worst record in the National League.

As of Sunday morning, their team batting WAR on FanGraphs was 5.5 while the team pitching WAR was 2.7. That's a combined total of 8.2, which was good for 12th-best in the majors—barely behind the then 19-15 Minnesota Twins; slightly ahead of the 20-14 Tampa Bay Rays.

Miami also entered play on Sunday with a plus-14 run differential and a Pythagorean record of 18-15. It was the 10th-best Pythagorean winning percentage at the time.

Unfortunately, heartbreaking losses have been the norm for the Marlins. They have lost in walk-off fashion three times already this season (with no such victories), plus eight other losses by one run. Seven of those painful losses came in the span of eight days (May 2-9), as they quickly went from four games above .500 to four games below.

But this team has the talent to contend, especially with Avisail Garcia and Jorge Soler both waking up from slow starts. The Marlins already had Jazz Chisholm Jr. and Pablo Lopez looking like stars, and perhaps things will start to swing back in their favor now that their two highly paid hitters are earning their keep.

As of Monday morning, the Pirates have the same 15-19 record as the Marlins.

But while the Fish have been unlucky to get to that point, the Buccos are lucky things haven't gone much worse.

The aforementioned team WAR where the Marlins rank 12th in the majors? Pittsburgh was 4.4 WAR behind Miami in 25th place overall. They also had a negative-57 run differential for a Pythagorean record of 11-22—just 0.5 games ahead of Cincinnati for the worst in the majors.

A big chunk of that run differential can be traced back to the 21-0 loss to the Cubs on April 23, but even if that had been a 21-0 win instead, they'd still be 14 runs in the hole for the year. That was an exceptionally bad day for the Pirates, but there's just not much here worth getting excited about aside from Ke'Bryan Hayes.

How bad will things actually get for the Pirates in their remaining 128 games?

Who the heck knows?

They recently inexplicably took two out of three against the Dodgers and then managed to beat the Reds 1-0 on Sunday despite not getting a single hit. That type of luck is bound to run out eventually, which could leave them battling Cincinnati and Detroit for the worst record in the bigs.